CN111905771B - Preparation method of catalyst for modifying cuprous oxide with different crystal faces by selenium - Google Patents

Preparation method of catalyst for modifying cuprous oxide with different crystal faces by selenium Download PDF

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CN111905771B
CN111905771B CN202010808847.8A CN202010808847A CN111905771B CN 111905771 B CN111905771 B CN 111905771B CN 202010808847 A CN202010808847 A CN 202010808847A CN 111905771 B CN111905771 B CN 111905771B
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catalyst
selenium
different crystal
crystal faces
modifying
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CN111905771A (en
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杨慧娟
王盛宝
李喜飞
张钰琳
易小宇
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Xian University of Technology
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/02Sulfur, selenium or tellurium; Compounds thereof
    • B01J27/057Selenium or tellurium; Compounds thereof
    • B01J27/0573Selenium; Compounds thereof
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/72Copper
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts

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Abstract

The invention discloses a preparation method of a catalyst for modifying cuprous oxide with different crystal faces by selenium, which comprises the following steps: weighing Cu 2 O and selenium powder are flatly paved at two ends of the magnetic boat, and then the magnetic boat is placed in a tube furnace for selenizing, thus obtaining the catalyst of the invention. The invention modifies selenium into Cu with different crystal faces 2 On O, the adsorption of Cu to OCHO is changed, and in addition, the side reaction is inhibited due to the doping of selenium, and finally, the Faraday efficiency of HCOOH is obviously improved. At the same time, pioneering study of Cu 2 Influence of selenization of different crystal planes of O on the Faraday efficiency of HCOOH, so that the crystal plane with the highest Faraday efficiency of HCOOH is obtained.

Description

Preparation method of catalyst for modifying cuprous oxide with different crystal faces by selenium
Technical Field
The invention belongs to the field of catalyst preparation, and particularly relates to a preparation method of a catalyst for modifying cuprous oxide with different crystal faces by selenium.
Background
In recent years, the global face of an increasingly serious energy crisis due to the reduction of fossil energy, and further, it is widely considered that CO generated by combustion of fossil energy 2 Is the main cause of greenhouse effect. Therefore, new energy is developed to replace fossil energy and reduce CO in the atmosphere 2 The content of (b) is currently a primary task. The research shows that under the action of the catalyst, CO 2 Can be converted into various reduction products, and therefore, research on the catalyst is hot. Among the numerous catalysts, the metal Cu is of great interest because Cu is the only one that can convert CO 2 Catalysts for reduction to various hydrocarbon products have problems of poor selectivity and reaction efficiency. Thus, increasing the selectivity of the product is the electrochemical reduction of CO 2 The first research task of (1). Among the numerous hydrocarbon products, formic acidIs attracting attention as a renewable clean energy source. However, the formic acid selectivity of Cu-based catalysts is too low to meet the needs of people. Therefore, it is an important research content to improve the selectivity of formic acid. Researches show that the yield of formic acid can be improved by the Cu group modified by selenium, and in addition, the influence of different crystal faces on formic acid selectivity is reported, but the improvement effect is not obvious. Therefore, the invention creatively provides a method for modifying Cu with different crystal faces by selenium 2 O (hexahedron, octahedron) method for improving yield of formic acid, and effectively improves CO 2 Yield of formic acid produced by reduction.
Disclosure of Invention
The invention aims to provide a preparation method of a catalyst for modifying cuprous oxide with different crystal faces by selenium, wherein the selenium modification is carried out on different crystal faces, so that CO is improved 2 The selectivity of formic acid in the reduction process solves the problem of CO 2 The yield of formic acid is low in the reduction process.
The technical scheme of the invention is as follows: a preparation method of a catalyst for modifying cuprous oxide with different crystal faces by selenium comprises the following steps:
weighing Cu 2 O and selenium powder are flatly paved at two ends of the magnetic boat, and then the magnetic boat is placed in a tube furnace for selenizing, thus obtaining the catalyst of the invention.
The technical solution adopted by the invention is also characterized in that,
Cu 2 the mass ratio of the O to the selenium powder is 1.5 to 3.
Cu 2 O may be hexahedral or octahedral.
The selenizing atmosphere in the selenizing process is Ar: h 2 And (3) =9 to 12, wherein the temperature is 25 to 360 ℃, and the temperature rise reaction time is 90 to 100 min.
Argon is introduced into the magnetic boat for 15 to 20 min before selenization.
The beneficial effects of the invention are: the preparation method can be used for treating Cu with different crystal faces 2 The selenium modification is carried out on O, the adsorption of Cu on the OCHO is changed after the selenium is added, in addition, the side reaction is inhibited due to the doping of the selenium, and finally, the Faraday efficiency of the HCOOH is obviously improved. At the same time, the invention is pioneeringCu 2 The influence of selenization of different crystal planes of O on the Faraday efficiency of HCOOH, so that the crystal plane with the highest Faraday efficiency of HCOOH is obtained.
Drawings
FIG. 1 is the hexahedral Cu selenide in example 2 of the present invention 2 O and heat treating Cu at the same temperature 2 O catalyst in CO 2 A Faraday efficiency comparison graph of formic acid under different reduction potentials in the reduction process;
FIG. 2 shows selenized octahedral Cu in example 5 of the present invention 2 O and heat treating Cu at the same temperature 2 O catalyst in CO 2 Graph comparing faradaic efficiency for formic acid at different reduction potentials during reduction.
Detailed Description
The invention is described in further detail below with reference to the drawings and the detailed description.
A preparation method of a catalyst for modifying cuprous oxide with different crystal faces by selenium specifically comprises the following steps:
pre-prepared hexahedral Cu 2 O and selenium powder are flatly paved at two ends of the magnetic boat according to the proportion of 1 (1.5 to 3), then the magnetic boat is placed in a tube furnace for selenization, and the selenization atmosphere is Ar: h 2 1 in the presence of H = (9 to 12): 1 2 Therefore, ar gas is introduced for 15 to 20 min before selenization so as to exhaust the air in the tube furnace and prevent explosion. And (3) during selenizing, controlling the temperature to be 25 to 360 ℃, and controlling the temperature-rising reaction time to be 90 to 100 min to obtain the catalyst of the invention.
A preparation method of a catalyst for modifying cuprous oxide with different crystal faces by selenium specifically comprises the following steps:
pre-prepared octahedral Cu 2 O and selenium powder are flatly paved at two ends of a magnetic boat according to the proportion of (1.5) to 3, then the magnetic boat is placed in a tube furnace for selenylation, and the selenylation atmosphere is Ar: h 2 1 in the presence of H = (9 to 12): 1 2 Therefore, ar gas is introduced for 15 to 20 min before selenization so as to exhaust the air in the tube furnace and prevent explosion. When selenizing is carried out, the temperature is 25 to 360 ℃, and the heating reaction time is 90 to 100 min, thus obtaining the catalyst of the invention.
Comparative example 1 hexahedral Cu 2 O heat treatment for preparing the catalyst:
pre-prepared hexahedral Cu 2 O is flatly laid in a magnetic boat and put into a tube furnace for heat treatment, and the treatment process is as follows: ar gas was introduced for 20 min before the heat treatment to evacuate the air in the tube furnace to prevent explosion. The heat treatment atmosphere is Ar: h 2 And (2) keeping the temperature at 360 ℃ and the temperature-rising reaction time at 100 min to obtain the catalyst of the invention.
Comparative example 2 octahedral Cu 2 O heat treatment for preparing the catalyst:
pre-prepared octahedral Cu 2 O is flatly laid in a magnetic boat and put into a tube furnace for heat treatment, and the treatment process is as follows: ar gas was introduced for 20 min before the heat treatment to evacuate the air in the tube furnace to prevent explosion. The heat treatment atmosphere is Ar: h 2 And (5) keeping the temperature at 360 ℃ for 100 min to obtain the catalyst of the invention.
Embodiment 1, a method for preparing a catalyst for modifying cuprous oxide with different crystal faces by selenium, specifically comprising the following steps:
pre-prepared hexahedral Cu 2 O and selenium powder are flatly paved at two ends of a magnetic boat according to the proportion of 1.5, and then the magnetic boat is placed in a tube furnace for selenylation, wherein the selenylation atmosphere is Ar: h 2 1, due to the presence of H =9 2 Therefore, argon gas is introduced for 15min before selenization to exhaust the air in the tube furnace, so as to prevent explosion. When the selenization is carried out, the temperature is 25 ℃, and the temperature-rising reaction time is 90min, thus obtaining the catalyst of the invention.
Embodiment 2, a method for preparing a catalyst for modifying cuprous oxide with different crystal faces by selenium, which specifically comprises the following steps:
pre-prepared hexahedral Cu 2 And O and selenium powder are flatly paved at two ends of the magnetic boat according to the proportion of 1: h 2 1, due to the presence of H 2 Therefore, argon gas is introduced for 20 min before selenization to exhaust the air in the tube furnace, so as to prevent explosion. During selenization, the temperature is 360 ℃, the temperature rise reaction time is 100 min, and the selenizing liquid is obtainedThe catalyst of (1).
Embodiment 3, a method for preparing a catalyst for modifying cuprous oxide with different crystal faces by selenium, which comprises the following steps:
preparing hexahedral Cu in advance 2 O and selenium powder are flatly paved at two ends of a magnetic boat according to the proportion of 1: h 2 1, due to the presence of H =10 2 Therefore, argon gas is introduced for 15min before selenization to exhaust the air in the tube furnace, so as to prevent explosion. During selenization, the temperature is 180 ℃, and the temperature rise reaction time is 95 min, so as to obtain the catalyst of the invention.
Embodiment 4, a method for preparing a catalyst for modifying cuprous oxide with different crystal faces by selenium, which comprises the following steps:
pre-prepared octahedral Cu 2 O and selenium powder are flatly paved at two ends of a magnetic boat according to the proportion of 1.5, and then the magnetic boat is placed in a tube furnace for selenylation, wherein the selenylation atmosphere is Ar: h 2 1, due to the presence of H =9 2 Therefore, argon gas is introduced for 15min before selenization to exhaust the air in the tube furnace, so as to prevent explosion. When the selenization is carried out, the temperature is 50 ℃, and the temperature rise reaction time is 90min, thus obtaining the catalyst of the invention.
Embodiment 5, a method for preparing a catalyst for modifying cuprous oxide with different crystal faces by selenium, which comprises the following steps:
pre-prepared octahedral Cu 2 O and selenium powder are flatly paved at two ends of a magnetic boat according to the proportion of 1: h 2 1, due to the presence of H 2 Therefore, argon is introduced for 20 min before selenization to exhaust the air in the tube furnace, so as to prevent explosion. During selenization, the temperature is 360 ℃, and the temperature-rising reaction time is 100 min, thus obtaining the catalyst of the invention.
Embodiment 6, a method for preparing a catalyst for modifying cuprous oxide with different crystal faces by selenium, which specifically comprises the following steps:
pre-prepared octahedral Cu 2 O and selenium powder are flatly paved at two ends of the magnetic boat according to the proportion of 1And placing the magnetic boat into a tube furnace for selenizing in Ar: h 2 1, due to the presence of H =10 2 Therefore, argon gas is introduced for 15min before selenization to exhaust the air in the tube furnace, so as to prevent explosion. During selenization, the temperature is 180 ℃, and the temperature rise reaction time is 95 min, thus obtaining the catalyst of the invention.
Selenized hexahedral Cu prepared in example 2 of the present invention 2 O catalyst and selenized octahedral Cu prepared in example 5 2 O catalyst, heat treated Cu prepared in comparative examples 1 and 2 2 O catalyst to CO 2 The research on electrochemical reduction performance is carried out in a two-chamber three-electrode reaction device, and the detection of the reduction product HCOOH is realized by using a nuclear magnetic resonance spectrometer. Of these, comparative examples 1 and 2 are for the purpose of excluding the influence of heat treatment on the catalyst. FIG. 1 is a selenated hexahedral Cu prepared in example 2 of the present invention 2 O, heat-treated hexahedral Cu prepared in comparative example 1 2 Faradaic efficiency comparison of O versus HCOOH, as can be seen from fig. 1: comparative heat treated hexahedral Cu 2 O, selenized Cu 2 The O hexahedron can generate significant FE of HCOOH under the reduction potential of 0.85V, and the FE is up to 12%. FIG. 2 shows the selenized Cu prepared in example 5 of the present invention 2 O octahedron, heat treated Cu prepared in comparative example 2 2 Faraday efficiency of O octahedra versus HCOOH, shown by FIG. 2, compared to untreated octahedral Cu 2 O, selenized octahedron, reaches the largest FE of HCOOH under the reduction potential of 0.95V, and is 9.2 percent. Contrasting hexahedral and octahedral Cu 2 O, which shows that the selectivity of the product can be obviously changed after different crystal faces are selenized, and hexahedral Cu 2 O has the greatest faraday efficiency of HCOOH.
The principle of the invention is as follows: the Cu with different crystal faces modified by selenium prepared by the invention 2 Compared with an undoped catalyst, the O catalyst changes the adsorption of Cu to OCHO after adding selenium, so that the Faraday efficiency of HCOOH is obviously improved, and CO 2 Side reactions during the reduction are also suppressed due to the doping of selenium. In particular, the different crystal planes Cu are selected in a targeted manner 2 Selenization treatment was performed on O to study the effect of selenium doping on HCOOH yield. Obtaining hexahedral Cu 2 O toolHas the best HCOOH selective performance.
The invention provides a preparation method of a catalyst for modifying cuprous oxide with different crystal faces by selenium, which effectively improves CO 2 Yield of formic acid in the reduction reaction. For CO 2 The improvement of the selectivity of formic acid in the reduction process is generally realized by the modes of morphology, oxidation state, addition of a second metal and the like, because the strategies can change the electronic structure of the reaction, thereby influencing the selectivity of formic acid. However, the faradaic efficiency of formic acid is still insufficient for human needs. Therefore, there is a need to develop a catalyst that can significantly improve the faradaic efficiency of formic acid. The invention pioneers the research on Cu with different crystal faces 2 Effect of O (hexahedral, octahedral) selenization on formic acid selectivity, of which hexahedral, octahedral, are more suitable for CO 2 Reduction reaction, and research shows that modification of selenium has certain promotion effect on generation of formic acid. During the selenization reaction, the set selenization atmosphere is (9 to 12): 1, because hydrogen is a reducing atmosphere and can form H with selenium 2 Selenium, further and Cu 2 And O reacts, the concentration is different, and the reaction degree is different. The catalyst prepared by the method can obviously improve the selectivity of the formic acid product.

Claims (2)

1. Catalyst for efficiently reducing CO 2 The application of the catalyst in formic acid generation is characterized in that the catalyst is prepared by the following steps:
weighing Cu 2 O and selenium powder are flatly paved at two ends of a magnetic boat, then the magnetic boat is placed in a tube furnace for selenylation, and the catalyst is obtained, wherein the Cu is 2 The mass ratio of O to the selenium powder is 1.5 to 3, and the selenizing atmosphere in the selenizing process is Ar: h 2 And (3) =9 to 12, wherein the temperature is 360 ℃, the heating reaction time is 90 to 100 min, and the Cu 2 O is hexahedron or octahedron.
2. The catalyst of claim 1 for efficient reduction of CO 2 The application of the selenizing agent in formic acid generation is characterized in that argon is introduced into a magnetic boat for 15-20 min before selenizing.
CN202010808847.8A 2020-08-12 2020-08-12 Preparation method of catalyst for modifying cuprous oxide with different crystal faces by selenium Active CN111905771B (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012197199A (en) * 2011-03-22 2012-10-18 Dowa Electronics Materials Co Ltd Copper selenide particle powder, and method for producing the same
CN107308959A (en) * 2017-07-18 2017-11-03 安徽师范大学 Cu2‑xSe nanometer sheet array foams carbon/carbon-copper composite material, preparation method and application
WO2018119543A1 (en) * 2016-12-29 2018-07-05 Pontificia Universidad Catolica De Chile Method for producing a cu2o/tio2 nanoparticle catalyst, and cu2o/tio2 nanoparticle catalyst
CN110694649A (en) * 2019-11-11 2020-01-17 南昌航空大学 Preparation method of copper selenide/titanium dioxide loaded visible light photocatalyst composite material

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103449385B (en) * 2012-05-28 2015-04-01 广东先导稀材股份有限公司 Preparation method of cuprous selenide
US20140339072A1 (en) * 2013-05-17 2014-11-20 Sunpower Technologies Llc Photocatalytic CO2 Reduction System
CN107519899B (en) * 2017-10-11 2020-10-13 陕西科技大学 Cobalt selenide cocatalyst, and preparation method and application thereof
CN110280277B (en) * 2019-07-17 2022-04-26 肇庆市华师大光电产业研究院 Carbon dioxide electrochemical reduction catalyst and preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012197199A (en) * 2011-03-22 2012-10-18 Dowa Electronics Materials Co Ltd Copper selenide particle powder, and method for producing the same
WO2018119543A1 (en) * 2016-12-29 2018-07-05 Pontificia Universidad Catolica De Chile Method for producing a cu2o/tio2 nanoparticle catalyst, and cu2o/tio2 nanoparticle catalyst
CN107308959A (en) * 2017-07-18 2017-11-03 安徽师范大学 Cu2‑xSe nanometer sheet array foams carbon/carbon-copper composite material, preparation method and application
CN110694649A (en) * 2019-11-11 2020-01-17 南昌航空大学 Preparation method of copper selenide/titanium dioxide loaded visible light photocatalyst composite material

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"金属和金属硫属化合物纳米晶的可控合成及其电催化性能研究";刘苏莉;《中国优秀博硕士学位论文全文数据库(博士) 工程科技Ⅰ辑》;20150715;第37-38页 *

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