CN108573124A - A kind of method of quantitative analysis metal insertion carbon nano-tube catalyst hydrogen evolution activity - Google Patents
A kind of method of quantitative analysis metal insertion carbon nano-tube catalyst hydrogen evolution activity Download PDFInfo
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Abstract
The invention discloses a kind of methods that quantitative analysis metal is embedded in carbon nanotube (MCNT) catalyst hydrogen evolution activity.The method of the present invention is simulated come the hydrogen evolution activity of quantitative analysis MCNT catalyst based on quantum chemistry density functional theory.By the stability study to MCNT models, model being stabilized property in evolving hydrogen reaction process is determined；It is screened according to adsorption potential, determines the specific location that catalyst surface evolving hydrogen reaction occurs；In conjunction with hydrogen adsorption free energy and evolving hydrogen reaction path computing, quantitative analysis goes out the hydrogen evolution activity of MCNT catalyst.This method includes the structure of MCNT catalyst models, the optimization of model structure, stable calculation, adsorption potential screening, hydrogen adsorption free energy and evolving hydrogen reaction path computing and hydrogen evolution activity analysis and characterization step.The present invention is not necessarily to carry out actual experiment and the practical synthesis of catalyst can be to the progress quantitative analysis of the hydrogen evolution activity of MCNT catalyst.
Description
Technical field
The present invention relates to the hydrogen evolution activity of carbon nano-tube material measurement, and in particular to a kind of this quantitative analysis metal insertion carbon
The method of nanotube (MCNT) catalyst hydrogen evolution activity.
Background technology
Fossil energy is non-renewable energy resources, and the burning of fossil energy will produce carbon dioxide and dust, is to cause
The principal element of global warming and environmental pollution.Hydrogen Energy can realize the regeneration of hydrogen as clean energy resource by evolving hydrogen reaction.
The method of hydrogen manufacturing at present mainly has hydrogen production from coal gasification technology, natural gas hydrogen preparation technology, biomass hydrogen preparation technology and water electrolysis hydrogen production
Technology.Compared to other hydrogen producing technologies, water electrolysis hydrogen production technology cleanliness without any pollution, stable yield and hydrogen purity obtained
Height, therefore water electrolysis hydrogen production technology is mostly used in commercial applications.Water electrolysis hydrogen production technology is to be passed through electric current in water by moisture
Son resolves into the process of hydrogen and oxygen, improves hydrogen output simultaneously to reduce electric quantity consumption, needs design stability efficiently electric
Electrode catalyst.Currently, the method evaluated the hydrogen evolution activity of electrode catalyst is mainly experimental method, that is, first pass through experiment
Then method synthetic catalyst carries out collecting gas test.But the environmental requirement of this method experimental implementation is harsh, laboratory apparatus is multiple
Miscellaneous, experimental expenses is expensive, and selects raw catelyst and prepare have blindness.
With the development of computer technology, quantum chemistry calculation simulation be increasingly being applied to the design of new material with
Research becomes a kind of research means laid equal stress on experimental method.The reaction that catalyst surface can occurs in it carries out simulation meter
It calculates, the catalytic activity of analysis of catalyst.Quantum chemistry calculation analogy method need to only be calculated on the basis of quantum-mechanical theory
Machine simulation calculate, without really being tested, it is efficient, at low cost, calculating cycle is short, it is repeatable height, result it is accurate, have
Universal directive significance.This makes quantum chemistry calculation analogue technique that the performance of new material not only can be predicted, and also has experimental method
The high efficiency not had can instruct the design, preparation and application of catalyst.However, at present, there are no utilizations in the world
The hydrogen evolution activity that quantum chemistry calculation analogy method is embedded in metal carbon nanotube (MCNT) catalyst carries out measurement and table in detail
The research case of sign.
Invention content
Present invention aims to overcome that the defect and deficiency of experimental technique, provide a kind of quantitative analysis metal insertion carbon nanometer
The method for managing (MCNT) catalyst hydrogen evolution activity.This method carrys out table based on the Density function theory in quantum chemistry calculation
It seeks peace and measures the hydrogen evolution activity of MCNT catalyst.By the meter for forming energy, phonon dispersion spectrum, first principle molecular dynamics
It calculates, determines the stability of the MCNT catalyst of design；The active sites occurred by the calculating of adsorption energy, quantitative analysis evolving hydrogen reaction
Point；By the calculating in evolving hydrogen reaction path, and hydrogen adsorption free energy is combined, analyzes the hydrogen evolution activity of MCNT catalyst.The present invention
Purpose be achieved through the following technical solutions：
A kind of method of quantitative analysis metal insertion carbon nano-tube catalyst hydrogen evolution activity, includes the following steps：
(1) catalyst model is built
According to carbon nanotube (CNT) model parameter, CNT models are imported into Materials Studio 7.0, in CNT
On produce defect, metallic atom (M) is embedded into defect, MCNT models are constructed.To fully consider hydrogen bond between hydrone
Effect, establish water layer model by the way that several hydrones are added.Water layer model and MCNT models are subjected to model docking, then
It is minimum that entire model is put into vacuum layer thicknessPeriodical box in, obtain simulation calculate metal insertion carbon nanometer
Manage (MCNT) catalyst model.According to the method described above, the adsorbates such as proton hydrate, hydrogen atom and hydrogen molecule are established out successively to exist
The adsorption structure model on the surfaces MCNT.
(2) model topology optimization
Model topology optimization is excellent to the model progress structure of initial construction by the calculating of quantum density functinal thory
Change, obtains stable structure.Evolving hydrogen reaction process includes that the silent reaction in Wall, the Paderewski reaction of extra large Lip river and Ta Feier react three bases
Elementary reaction.Model topology optimization is related to possible reactant, intermediate and product during evolving hydrogen reaction, include atom, from
By base and molecule；The eutectoid content knot for also relating to relative species in each elementary reaction initial state (IS) and final states (FS) is calculated simultaneously
Structure.Electron exchange function is using generalized gradient approximation (GGA) PBE and DNP base groups, convergence during structure optimization
0.00001Ha。
(3) stable calculation
Stable calculation is related to the formation energy of MCNT catalyst models, phonon dispersion spectrum and first principle molecular dynamics
It calculates.Being formed can averagely arrive the energy overcome required for each atom when condensed state material is resolved into isolated monatomic.
When the formation of material can be less than zero when, can just form stable structure, and formed can more negative indication structure it is more stable.Phonon
What dispersion spectrum reflected is the relationship of phonon energy and momentum, when the frequency of phonon vibrations is all that the bright structure of real frequency schedule is in correlation
The local smallest point of potential energy level, corresponding is rock-steady structure.First principle molecular dynamics is by density functional theory and to divide
The method that subdynamics combine, it can combine the structure of temperature and Density function theory in molecular dynamics
Come, the configuration state of material at the corresponding temperature is predicted by the variation of bond distance between observation material atom, if bond distance is balancing
Position is fluctuated up and down, then certification structure can be stabilized, if bond distance deviates equilbrium position, certification structure stability is broken
It is bad.
(4) adsorption potential screening calculates
Stablize absorption on the surfaces MCNT based on the adsorbate (such as proton hydrate, hydrogen atom and hydrogen molecule) after structure optimization
Structure determines that adsorbate in the adsorption potential on the surfaces MCNT, and calculates the energy of each adsorption structure, passes through and calculate adsorption structure
Energy with absorption before adsorbate energy and MCNT energy difference, obtain adsorbate this adsorption potential adsorption energy.Adsorption energy is got over
The easier absorption adsorbate of negative adsorption potential, is more conducive to the generation of evolving hydrogen reaction.It is big by comparing the adsorption energy of each adsorption potential
It is small, determine optimal adsorption potential, i.e., the optimal location that evolving hydrogen reaction occurs in MCNT catalyst surfaces.
(5) hydrogen adsorption free energy and evolving hydrogen reaction path computing
Pass through hydrogen atom (i.e. adsorbate) free energy and MCNT free energys before subtracting absorption with the free energy of hydrogen adsorption structure
Hydrogen adsorption free energy is calculated.Evolving hydrogen reaction path is related to the silent reaction in Wall, the Paderewski reaction of extra large Lip river and Ta Feier reactions three
A elementary reaction.From the rock-steady structure of reaction initial state and final states, atom pairing is carried out to the initial state of each reaction, final states,
Then the search for carrying out reaction transition state (TS) calculates, and acquires the transition state in each reaction, then to initial state, transition state, final states
It makes energy calculation.Frequency calculating is carried out to initial state, transition state, final states, zero point energy is carried out to the energy value acquired and Entropy Changes is repaiied
Just, the structure and energy variation in entire response path network and its reaction are finally obtained.
(6) analysis of catalyst hydrogen evolution activity and characterization
Data are calculated according to hydrogen adsorption free energy, hydrogen adsorption free energy more just, is more unfavorable for fertile during evolving hydrogen reaction
The generation of Er Mo reactions, hydrogen adsorption free energy is more negative, and the reaction of extra large Lip river Paderewski and tower being more unfavorable for during evolving hydrogen reaction are luxuriant and rich with fragrance
The generation of your reaction.Therefore, hydrogen adsorption free energy is higher closer to zero, MCNT catalyst hydrogen evolution activities.By response path,
It determines reaction energy barrier, in conjunction with evolving hydrogen reaction path network, determines the rate determining step of control evolving hydrogen reaction rate.React energy
Lower, the easier progress of reaction is built, the hydrogen evolution activity for corresponding to MCNT catalyst is higher.
Advantages of the present invention and effect：The present invention overcomes existing experimental technique to liberation of hydrogen reality without carrying out actual experiment
The problem of testing equipment and corresponding operating complexity and experiment synthesizing new liberation of hydrogen catalyst blindness.The present invention is based on by using
The method of quantum chemistry density functional theory carries out simulation calculating, and association reaction to the response path during evolving hydrogen reaction
Hydrogen adsorption free energy in the process and reaction energy barrier carry out network analysis to the hydrogen evolution activity of Performances of Novel Nano-Porous mitron catalyst.
Description of the drawings
Fig. 1 is the detailed step figure of quantitative analysis metal insertion carbon nanocatalyst hydrogen evolution activity of the present invention.
Fig. 2 is model foundation process, wherein (a) is MnCNT (5,5) model foundation process；(b) it is water layer model；(c) it is
MnCNT (5,5) catalyst model.
Fig. 3 is the rock-steady structure after structure optimization, wherein (a) is the vertical view and side view of MnCNT (5,5)；(b)、
(c), (d), (e) and (f) are the possible adsorption structures of single hydrogen atom；(g), (h), (i), (j) and (k) are in first hydrogen original
After son determines adsorption potential, second possible adsorption structure of hydrogen atom；(l) and (m) is MnCNT (5,5) catalytic hydrogen evolution respectively
The initial state of the silent reaction in Wall and final states structure in the process；(n) and (o) is extra large love during MnCNT (5,5) catalytic hydrogen evolution respectively
The initial state of Si Ji reactions and final states structure；(p) and (q) be respectively during MnCNT (5,5) catalytic hydrogen evolution Ta Feier react just
State and final states structure.
Fig. 4 is MnCNT (5,5) stable calculation data, wherein (a) is the phonon dispersion spectrum of MnCNT (5,5)；(b)、(c)
(d) it is that the variation of the Mn-C bond distance in the 1ps of first principle molecular dynamics simulation at 300K, 500K, 800K becomes respectively
Gesture.
Fig. 5 is adsorption potential screening computation model, wherein (a) indicates the single all possible adsorption potential of hydrogen atom, arrow table
Show the transfer case that hydrogen atom occurs during structure optimization；(b) it indicates after T adsorption potentials have adsorbed a hydrogen atom,
Second all possible adsorption potential of hydrogen atom, arrow indicate the transfer case that hydrogen atom occurs in configuration process.
Fig. 6 is evolving hydrogen reaction path, wherein (a) is evolving hydrogen reaction path network；(b) it is the silent response path in Wall；(c) extra large
Lip river Paderewski response path；(d) it is Ta Feier response paths.
Fig. 7 is carbon nanotube (CNT) curvature and hydrogen adsorption free energy relational graph of MnCNT.
Fig. 8 is embedded metal species (M) and MCNT hydrogen adsorption free energy relational graphs.
Specific implementation mode
Detailed step such as Fig. 1 institutes of the method for the hydrogen evolution activity of quantitative analysis metal insertion carbon nano-tube catalyst of the present invention
Show, the catalyst that the present invention will be described in detail for (5,5) type carbon nanotube (MnCNT (5,5)) is embedded in manganese metal (Mn) below
Model construction, model topology optimization, stable calculation, adsorption potential screening, hydrogen adsorption free energy and evolving hydrogen reaction path computing with
And catalyst hydrogen evolution activity is analyzed and characterization.It should be understood that following content is merely to illustrate the present invention rather than the limitation present invention
Range.
1 quantitative analysis metal of embodiment is embedded in the hydrogen evolution activity of carbon nanotube MnCNT (5,5) catalyst
(1) MnCNT (5,5) catalyst model is built
(5,5) type carbon nanotube (CNT (5,5)) model is imported into Material Studio 7.0, in CNT (5,5)
On the basis of model, carbon nanotube tangentially upper two adjacent carbon atoms are removed, then the embedded Mn atoms in the defect of generation,
Manganese insertion carbon nanotube (MnCNT (5,5)) model is constructed, is established shown in process such as Fig. 2 (a).To fully consider between hydrone
Hydrogen bond action, establish the water layer model such as Fig. 2 (b) shown in, the hydrogen bond action in figure between dotted line expression hydrone.By water layer mould
Type is completely covered on above the metal center of MnCNT (5,5) model, completes the docking of water layer model and MnCNT (5,5) model,
It is minimum entire model is put into vacuum layer thicknessPeriodical box in, obtain simulation calculate MnCNT (5,5) urge
Agent model, shown in final mask such as Fig. 2 (c).According to the method described above, proton hydrate, hydrogen atom and hydrogen molecule are established out successively
Adsorption structure model of the equal adsorbates in MnCNT (5,5) catalyst surface.
(2) model topology optimization
To the model of all foundation in step (1), with the Dmol of Material Studio 7.03Module carries out structure
Optimization.Structure optimization calculating is carried out using density functional theory, wherein electron exchange function is generalized gradient approximation (GGA) PBE
With DNP base groups, convergence is 0.00001Ha.Fig. 3 is the rock-steady structure after structure optimization, and wherein Fig. 3 (a) is MnCNT
(5,5) vertical view and side view；Fig. 3 (b), Fig. 3 (c), Fig. 3 (d), Fig. 3 (e) and Fig. 3 (f) are the possible suctions of single hydrogen atom
Attached structure；Fig. 3 (g), Fig. 3 (h), Fig. 3 (i), Fig. 3 (j) and Fig. 3 (k) are after first hydrogen atom determines adsorption potential second
A possible adsorption structure of hydrogen atom；Fig. 3 (l) and Fig. 3 (m) is the silent reaction in Wall during MnCNT (5,5) catalytic hydrogen evolution respectively
Initial state and final states structure；Fig. 3 (n) and Fig. 3 (o) is that extra large Lip river Paderewski reacts MnCNT (5,5) catalytic hydrogen evolution in the process respectively
Initial state and final states structure；Fig. 3 (p) and Fig. 3 (q) be respectively the initial state that Ta Feier reacts during MnCNT (5,5) catalytic hydrogen evolution and
Final states structure.
(3) stable calculation
It sets out from the MnCNT (5,5) (Fig. 3 (a)) of structure optimization, carrying out single-point to it can calculate, then to free state
Manganese atom and carbon atom, which carry out single-point, to be calculated, and respective energy is obtained, and the formation for acquiring MnCNT (5,5) can be -7.54eV,
MnCNT (5,5) is as broken to the required energy of single atom, it is anti-that this number is much larger than generation liberation of hydrogen on the surface thereof
The energy that should more need illustrates that MnCNT (5,5) is stable at reaction conditions.
Fig. 4 (a) is the phonon dispersion spectrum of MnCNT (5,5), and the frequency of phonon vibration is all that (i.e. frequency is just, to be more than to real frequency
Zero) show that structure is in the local smallest point in relevant potential face, corresponding MnCNT (5,5) is rock-steady structure.Fig. 4 (b), Fig. 4
(c) and Fig. 4 (d) is (5,5) MnCNT in the 1ps of first principle molecular dynamics simulation at 300K, 500K, 800K respectively
The trend chart of middle Mn-C bond distance.It can be seen that Mn-C bond distance stablizes in 300K, 500K, 800K Up and down
Fluctuation shows that Mn-C keys are no in 300K, 500K, 800K and is broken that MnCNT (5,5) structure is stabilized.
(4) adsorption potential screens
The various states models that may adsorb are set out on MnCNT (5,5) surface from Fig. 3, and carrying out single-point respectively can calculate, with asking
The energy obtained calculates separately out the corresponding adsorption energy of each adsorption potential.Indicate single hydrogen atom on MnCNT (5,5) surface in Fig. 5 (a)
Upper all possible adsorption potential.Arrow expression is during structure optimization, the transfer case of hydrogen atom generation.Calculation shows that tying
Hydrogen atom in structure optimization process on MnCNT (5,5) surface on B1, B3, B4 adsorption potential can be transferred to T2 adsorption potentials, H1 adsorption potentials
Hydrogen atom can be transferred to T1 adsorption potentials, the hydrogen atom of B2 adsorption potentials can be transferred to T3 adsorption potentials, the hydrogen atom meeting of B5 adsorption potentials
T4 adsorption potentials are transferred to, the single hydrogen atom as shown in Figure 3 all possible absorption on MnCNT (5,5) surface is finally obtained
State, it is as shown in table 1 that calculating acquires the corresponding adsorption energy of each adsorption potential.
The adsorption energy of 1 single hydrogen atom of table each adsorption potential on MnCNT (5,5) surface
Adsorption energy is more negative, indicates that hydrogen atom is more easily also more likely to be adsorbed on the adsorption potential, from table 1 it follows that
T2 adsorption potentials are the optimal adsorption potentials of single hydrogen atom on MnCNT (5,5) surface.Based on monatomic optimal adsorption potential (Fig. 5 (b)
Middle T adsorption potentials) absorption one hydrogen atom after, Fig. 5 (b) gives second hydrogen atom and is possible on MnCNT (5,5) surface
Adsorption potential, arrow indicate during structure optimization hydrogen atom occur transfer case.Calculation shows that in structure optimization process
Hydrogen atom on middle MnCNT (5,5) surface on B2 adsorption potentials can be transferred to T2 adsorption potentials, the hydrogen atom meeting on H1 and B1 adsorption potentials
T1 adsorption potentials are transferred to, the Hydrogen transfer of B3 and H2 adsorption potentials finally obtains all possible as shown in Figure 3 to T3 adsorption potentials
Double Hydrogen chemisorption states, it is as shown in table 2 that calculating acquires the corresponding adsorption energy of each adsorption potential.From Table 2, it can be seen that at first
After the T adsorption potentials of MnCNT (5,5), second hydrogen atom most probable is adsorbed on T5 adsorption potentials Hydrogen chemisorption.
The adsorption energy of 2 second hydrogen atoms of table each adsorption potential on MnCNT (5,5) surface
(5) hydrogen adsorption free energy and evolving hydrogen reaction path computing
Respectively from the silent reaction in the Wall of liberation of hydrogen process on MnCNT in Fig. 3 (5,5) catalyst surface, the Paderewski reaction of extra large Lip river
Initial state and final states structure with Ta Feier reactions are set out, and calculate the transition state in search reaction, then carry out energy meter to transition state
It calculates, finally obtains entire evolving hydrogen reaction path.The silent reaction in Wall is a proton hydrate in water layer under being dissociated in hydrone
Come, is adsorbed onto the process of MnCNT (5,5) catalyst surface；Extra large Lip river Paderewski reaction is a proton hydrate and MnCNT in water layer
(5,5) the hydrogen atom association reaction of Adsorption on Surface generates the process of hydrogen；Ta Feier reactions are two proton hydrates from moisture
Catalyst surface is disintegrated down while is adsorbed in son, and common desorption combines the process for generating hydrogen.Fig. 6 (a) indicates that liberation of hydrogen is anti-
The response path network answered is divided into two response paths, i.e. Wall Mo-Hai Luo Paderewskis response path and Wall Mo-Ta Feier
Response path.(b) it is the silent response path in Wall on MnCNT (5,5) surface, reaction energy barrier 0.61eV；(c) it is MnCNT
Extra large Lip river Paderewski response path on (5,5) surface, reaction energy barrier 0.80eV；(d) it is the tower on MnCNT (5,5) surface
Fei Er response paths, reaction energy barrier 1.72eV.In addition, calculation shows that absorption of the hydrogen atom on MnCNT (5,5) surface from
By that can be+0.118+eV.
(6) analysis of MCNT catalyst hydrogen evolution activity and characterization
Theoretically for adsorption free energy closer to zero, the hydrogen evolution activity of catalyst is higher.The hydrogen absorption of MnCNT (5,5) is certainly
By that can be 0.118eV, it be comparatively close to zero, illustrates that MnCNT (5,5) has high hydrogen evolution activity.On the other hand, MnCNT (5,5) table
On face the reaction energy barrier of the silent reaction in Wall, the Paderewski reaction of extra large Lip river and Ta Feier reactions be respectively 0.61eV, 0.80eV and
1.72eV shows that MnCNT (5,5) catalyst surface is conducive to the generation of Wall Mo-Hai Luo Paderewskis reaction, is evolving hydrogen reaction
Predominating path, rate determining step are the Paderewski reaction of extra large Lip river, and reaction energy barrier is only 0.80eV, further illustrates MnCNT
(5,5) catalyst surface is easy to happen evolving hydrogen reaction, and the hydrogen evolution activity of MnCNT (5,5) catalyst is very high.
The MnCNT evolving hydrogen reaction energy barrier (units of 3 different curvature of table：eV)
It is similar with the process of calculation analysis of MnCNT (5,5), it has further calculated the MnCNT with different CNT curvature and has been catalyzed
The hydrogen adsorption free energy of agent and evolving hydrogen reaction path analyze influence of the CNT curvature to MnCNT catalyst hydrogen evolution activities.Mn is embedding
(3,3), (5,5), (7,7) and (9,9) the type carbon nanotube entered be denoted as respectively MnCNT (3,3), MnCNT (5,5), MnCNT (7,
And MnCNT (9,9) 7).Table 3 gives the hydrogen absorption of MnCNT (3,3), MnCNT (5,5), MnCNT (7,7) and MnCNT (9,9)
Free energy and evolving hydrogen reaction energy barrier.Fig. 7 gives the hydrogen adsorption free energy for the MnCNT for having come out different curvature.As shown in Figure 7, MnCNT
(3,3), the hydrogen adsorption free energy of MnCNT (5,5), MnCNT (7,7) and MnCNT (9,9) be respectively+0.363eV ,+0.118eV,
+ 0.184eV and+0.190eV illustrates that the increase with carbon nanotube curvature, hydrogen adsorption free energy are presented " V " type curve and close
Increased trend after first reduction is presented in system, i.e. hydrogen adsorption energy, and the hydrogen adsorption free energy of wherein MnCNT (5,5) is minimum, also closest
Zero.This shows that " volcano " type curved line relation, i.e. MnCNT is presented in the increase with carbon nanotube curvature, the hydrogen evolution activity of MnCNT
The trend of first increases and then decreases, the hydrogen evolution activity highest of wherein MnCNT (5,5) is presented in hydrogen evolution activity.In addition, table 3 gives not
With the MnCNT evolving hydrogen reaction energy barriers of curvature.It is as can be seen from Table 3, similar with the evolving hydrogen reaction path on MnCNT (5,5) surface,
The predominating path of the liberation of hydrogen process of MnCNT (3,3), MnCNT (7,7) and MnCNT (9,9) is also that Wall Mo-Hai Luo Paderewskis are anti-
It answers, rate determining step is the Paderewski reaction of extra large Lip river, and corresponding reaction energy barrier is respectively 1.87eV, 1.08eV and 1.27eV.
With the increase of carbon nanotube curvature, the evolving hydrogen reaction energy barrier of MnCNT is also presented " V " type curved line relation, evolving hydrogen reaction energy barrier into
One step shows that " volcano " type curved line relation, the hydrogen evolution activity highest of wherein MnCNT (5,5) is presented in corresponding MnCNT hydrogen evolution activities.
Influence for the embedded metal species of analysis to MCNT hydrogen evolution activities, respectively by Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn is embedded into (5,5) type carbon nanotube, obtains TiCNT (5,5), VCNT (5,5), CrCNT (5,5), MnCNT (5,5), FeCNT
(5,5), CoCNT (5,5), NiCNT (5,5), CuCNT (5,5) and ZnCNT (5,5).Fig. 8 gives the carbon of different metal insertion
The hydrogen adsorption free energy of nanotube and pure Pt.By in figure it is found that its hydrogen adsorption free energy sequence is：Pure Pt (- 0.090eV)<
MnCNT(5,5)(+0.118eV)<FeCNT(5,5)(-0.146eV)<VCNT(5,5)(-0.273eV)<CrCNT(5,5)(-
0.351eV)<CoCNT(5,5)(-0.424eV)<CuCNT(5,5)(-0.484eV)<TiCNT(5,5)(-0.540eV)<NiCNT
(5,5)(-0.926eV)<ZnCNT(5,5)(-1.103eV).The result shows that the hydrogen adsorption free energy of pure Pt it is minimum (-
0.090eV), corresponding hydrogen evolution activity highest.In the carbon nanotube of various metals insertion, the hydrogen absorption of MnCNT (5,5) is freely
It can be only second to Pt and close to zero, show in the carbon nanotube that various metals are embedded in, the liberation of hydrogen of MnCNT (5,5) catalyst is lived
Property highest.
Table 4 provides the evolving hydrogen reaction energy barrier of MCNT (5,5) catalyst of different metal atom indentation.As can be seen from Table 4,
MCNT (5, the 5) catalyst for all metallic atoms insertion being related to all follows Wall Mo-Hai Luo Paderewskis reaction, corresponding rate
Rate-determining steps are the Paderewski reaction of extra large Lip river.TiCNT(5,5)、VCNT(5,5)、CrCNT(5,5)、MnCNT(5,5)、FeCNT(5,
5), the evolving hydrogen reaction energy barrier of CoCNT (5,5), NiCNT (5,5), CuCNT (5,5) and ZnCNT (5,5) are respectively 1.88eV,
1.22eV, 1.32eV, 0.80eV, 1.20eV, 1.39eV, 2.03eV, 1.52eV and 2.83eV illustrate MnCNT (5,5) catalyst
Hydrogen evolution activity highest, with hydrogen adsorption free energy analysis result it is consistent.
MCNT (5,5) evolving hydrogen reaction energy barrier (unit of 4 different metal atom indentation of table：eV)
Claims (4)
1. a kind of method of quantitative analysis metal insertion carbon nano-tube catalyst hydrogen evolution activity, it is characterised in that including walking as follows
Suddenly：
(1) catalyst model is built
According to carbon nanotube (CNT) model parameter, CNT models are imported into Materials Studio 7.0, are made on CNT
Defect is produced, metallic atom (M) is embedded into defect, MCNT models are constructed；To fully consider the work of hydrogen bond between hydrone
With establishing water layer model by the way that several hydrones are added；Water layer model and MCNT models are subjected to model docking, it then will be whole
It is minimum that a model is put into vacuum layer thicknessPeriodical box in, obtain simulation calculate metal insertion carbon nanotube
(MCNT) catalyst model；According to the method described above, the adsorbates such as proton hydrate, hydrogen atom and hydrogen molecule are established out successively in MCNT
The adsorption structure model on surface；
(2) model topology optimization
Model topology optimization is to calculate to carry out structure optimization to the model of initial construction by quantum density functinal thory, is obtained
To stable structure；Evolving hydrogen reaction process includes that the silent reaction in Wall, the Paderewski reaction of extra large Lip river and Ta Feier three primitives of reaction are anti-
It answers；Model topology optimization is related to possible reactant, intermediate and product during evolving hydrogen reaction, including atom, free radical and
Molecule；The eutectoid content structure for also relating to relative species in each elementary reaction initial state (IS) and final states (FS) is calculated simultaneously；Structure
Electron exchange function uses generalized gradient approximation (GGA) PBE and DNP base groups in optimization process, and convergence is 0.00001Ha；
(3) stable calculation
Stable calculation is related to the formation energy of MCNT catalyst models, phonon dispersion spectrum and first principle molecular dynamics meter
It calculates；Being formed can averagely arrive the energy overcome required for each atom when condensed state material is resolved into isolated monatomic；When
The formation of material can be less than zero when, can just form stable structure, and formed can more negative indication structure it is more stable；Phonon color
Dissipate spectrum reflection is the relationship of phonon energy and momentum, when the frequency of phonon vibrations is all that the bright structure of real frequency schedule is in Related Potentials
The local smallest point in energy face, corresponding is rock-steady structure；First principle molecular dynamics is by density functional theory and molecule
The method that dynamics combines, it can combine the structure of temperature and Density function theory in molecular dynamics,
The configuration state of material at the corresponding temperature is predicted by the variation of bond distance between observation material atom, if bond distance is in equilbrium position
Fluctuation up and down, then certification structure can be stabilized, if bond distance deviates equilbrium position, certification structure stability is destroyed；
(4) adsorption potential screens
Stablize absorption knot on the surfaces MCNT based on the adsorbate (such as proton hydrate, hydrogen atom and hydrogen molecule) after structure optimization
Structure determines that adsorbate in the adsorption potential on the surfaces MCNT, and calculates the energy of each adsorption structure, passes through the energy for calculating adsorption structure
Amount with absorption before adsorbate energy and MCNT energy difference, obtain adsorbate this adsorption potential adsorption energy；Adsorption energy is more negative
The easier absorption adsorbate of adsorption potential, be more conducive to the generation of evolving hydrogen reaction；The adsorption energy size of each adsorption potential by comparing,
Determine optimal adsorption potential, i.e., the optimal location that evolving hydrogen reaction occurs in MCNT catalyst surfaces；
(5) hydrogen adsorption free energy and evolving hydrogen reaction path computing
It is calculated by hydrogen atom (i.e. adsorbate) free energy before subtracting absorption with the free energy of hydrogen adsorption structure and MCNT free energys
Obtain hydrogen adsorption free energy；Evolving hydrogen reaction path is related to the silent reaction in Wall, the Paderewski reaction of extra large Lip river and Ta Feier and reacts three bases
Elementary reaction；From the rock-steady structure of reaction initial state and final states, atom pairing is carried out to the initial state of each reaction, final states, then
The search for carrying out reaction transition state (TS) calculates, and acquires the transition state in each reaction, then carry out to initial state, transition state, final states
Energy balane；Frequency calculating is carried out to initial state, transition state, final states, zero point energy and Entropy Changes amendment are carried out to the energy value acquired, most
The structure and energy variation in entire response path network and its reaction are obtained eventually；
(6) analysis of catalyst hydrogen evolution activity and characterization
Data are calculated according to hydrogen adsorption free energy, more just, the Wall being more unfavorable for during evolving hydrogen reaction is silent for hydrogen adsorption free energy
The generation of reaction, hydrogen adsorption free energy is more negative, and the reaction of extra large Lip river Paderewski and Ta Feier being more unfavorable for during evolving hydrogen reaction are anti-
The generation answered；Therefore, hydrogen adsorption free energy is higher closer to zero, MCNT catalyst hydrogen evolution activities；By response path, determine
Reaction energy barrier determines the rate determining step of control evolving hydrogen reaction rate in conjunction with evolving hydrogen reaction path network；Reaction energy barrier is got over
It is low, easier progress is reacted, the hydrogen evolution activity of corresponding MCNT catalyst is higher.
2. the method for quantitative analysis metal insertion carbon nano-tube catalyst hydrogen evolution activity according to claim 1, feature
It is：The characterization method be formed energy, phonon dispersion spectrum, first principle molecular dynamics, hydrogen adsorption free energy and
Evolving hydrogen reaction path.
3. the method for quantitative analysis metal insertion carbon nano-tube catalyst hydrogen evolution activity according to claim 1, feature
It is：The metal M is Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn.
4. the method for quantitative analysis metal insertion carbon nano-tube catalyst hydrogen evolution activity according to claim 1, feature
It is：The carbon nanotube CNT is CNT (3,3), CNT (5,5), CNT (7,7) and CNT (9,9) type carbon nanotube.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109785911A (en) * | 2019-01-03 | 2019-05-21 | 广州供电局有限公司 | The determination method and apparatus of gas and metal material surface adsorpting type |
| CN113674812A (en) * | 2021-07-30 | 2021-11-19 | 哈尔滨工业大学 | Design method of metal-nitrogen-carbon nitrogen fixation electrocatalyst |
| CN113782106A (en) * | 2021-07-29 | 2021-12-10 | 空气动力学国家重点实验室 | Solving method for high enthalpy dissociation gas surface catalytic reaction rate for CFD |
| CN114381742A (en) * | 2022-01-14 | 2022-04-22 | 河南师范大学 | Nonmetal monatomic doped BSe monolayer hydrogen evolution catalyst, design method and application |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1876548A1 (en) * | 2006-07-06 | 2008-01-09 | Institut Catala D'Investigacio Quimica | Computational method for the prediction of enantiomeric excesses and absolute configurations by using DFT-based 3D descriptors |
| CN103793622A (en) * | 2014-03-11 | 2014-05-14 | 中国石油大学(华东) | Method for analyzing influences of reaction intermediate on catalyst activity |
| CN103870644A (en) * | 2014-03-11 | 2014-06-18 | 中国石油大学(华东) | Method for identifying MoP catalyst denitrification active sites |
| CN103869045A (en) * | 2014-03-27 | 2014-06-18 | 中国石油大学(华东) | Method for testing activity of methanol fuel cell anode material |
| CN103936597A (en) * | 2013-01-22 | 2014-07-23 | 拜尔材料科学股份公司 | Apparatus and method for producing aromatic amines |
| US20150178475A1 (en) * | 2013-12-19 | 2015-06-25 | Chevron Phillips Chemical Company Lp | Selective Oligomerization Catalysts and Methods of Identifying Same |
-
2018
- 2018-05-15 CN CN201810459006.3A patent/CN108573124B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1876548A1 (en) * | 2006-07-06 | 2008-01-09 | Institut Catala D'Investigacio Quimica | Computational method for the prediction of enantiomeric excesses and absolute configurations by using DFT-based 3D descriptors |
| CN103936597A (en) * | 2013-01-22 | 2014-07-23 | 拜尔材料科学股份公司 | Apparatus and method for producing aromatic amines |
| US20150178475A1 (en) * | 2013-12-19 | 2015-06-25 | Chevron Phillips Chemical Company Lp | Selective Oligomerization Catalysts and Methods of Identifying Same |
| CN103793622A (en) * | 2014-03-11 | 2014-05-14 | 中国石油大学(华东) | Method for analyzing influences of reaction intermediate on catalyst activity |
| CN103870644A (en) * | 2014-03-11 | 2014-06-18 | 中国石油大学(华东) | Method for identifying MoP catalyst denitrification active sites |
| CN103869045A (en) * | 2014-03-27 | 2014-06-18 | 中国石油大学(华东) | Method for testing activity of methanol fuel cell anode material |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109785911A (en) * | 2019-01-03 | 2019-05-21 | 广州供电局有限公司 | The determination method and apparatus of gas and metal material surface adsorpting type |
| CN113782106A (en) * | 2021-07-29 | 2021-12-10 | 空气动力学国家重点实验室 | Solving method for high enthalpy dissociation gas surface catalytic reaction rate for CFD |
| CN113782106B (en) * | 2021-07-29 | 2024-04-16 | 空气动力学国家重点实验室 | Solving method for high enthalpy dissociation gas surface catalysis reaction rate for CFD |
| CN113674812A (en) * | 2021-07-30 | 2021-11-19 | 哈尔滨工业大学 | Design method of metal-nitrogen-carbon nitrogen fixation electrocatalyst |
| CN114381742A (en) * | 2022-01-14 | 2022-04-22 | 河南师范大学 | Nonmetal monatomic doped BSe monolayer hydrogen evolution catalyst, design method and application |
| CN114381742B (en) * | 2022-01-14 | 2024-03-12 | 河南师范大学 | Nonmetallic monoatomic doping BSe monolayer hydrogen evolution catalyst, design method and application |
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