A kind of acid pickling macromolecule proton exchange membrane and preparation method thereof
Technical field
The present invention relates to the high temperature proton exchange film fuel cell composite membrane, specifically a kind of acid pickling macromolecule compound proton exchange membrane and preparation method thereof.
Background technology
Proton Exchange Membrane Fuel Cells (PEMFC) is a kind of power generation assembly that the chemical energy in fuel and the oxygenant is directly changed into electric energy by electrochemical reaction.Its critical material comprises the ionogen of the solid polymer membrane with good proton-conducting, and the cathode and anode be made up of Catalytic Layer and gas diffusion layers of film both sides.Anode, solid polymer electrolytic film and negative electrode three press together and constitute Proton Exchange Membrane Fuel Cells (PEMFC) core component---membrane electrode three-in-one (MEA), the three-in-one both sides of membrane electrode are provided with the graphite cake of gas flow channel or surface modification of metals plate (bipolar plates) back constitutes the Proton Exchange Membrane Fuel Cells monocell, and several are superimposed and constitute pile in the pressure filter mode to hundreds of monocells.During oxygenants such as fuel such as antianode hydrogen supply or reformed gas, anticathode supply oxygen or air, go up the generation electrochemical reaction, the chemical energy in fuel and the oxygenant is converted into electric energy at membrane electrode three-in-one (MEA).
Proton exchange membrane is the PEMFC key part, and it directly influences battery performance and life-span.The proton exchange membrane that is used for PEMFC must satisfy following condition:
(1) has high H
+Transmissibility, generally speaking specific conductivity will reach the order of magnitude of 0.01S/cm;
(2) under the condition of PEMFC operation promptly in battery operated temperature, under the operating potential of oxidation and reducing atmosphere and electrode, membrane structure and composition remain unchanged, and promptly have good chemistry and electrochemical stability spare;
(3) no matter film all should have the permeability coefficient of low reactant gases such as hydrogen, oxygen at dry state or hygrometric state (full suction), guarantee that battery has high faraday (enclosed pasture) efficient.
(4) a certain temperature before the film resin decomposition temperature such as vitrifying or near second-order transition temperature, the film surface has certain visco-elasticity combine the minimizing contact resistance in order to electrocatalyst layers when the preparation membrane electrode is three-in-one and film;
(5) no matter at dry state or hygrometric state, film all should have certain mechanical strength, is suitable for the assembling of three-in-one preparation of membrane electrode and series of cells.
At present, people just are being devoted to develop high temperature proton exchange film, because along with the raising in proton exchange membrane work permissible temperature interval, bring a series of advantage to PEMFC, aspect electrochemistry, show as: help CO and pay with taking off, improve anti-CO ability in the anodic oxidation; Reduce the redox overpotential of negative electrode; Improve activity of such catalysts; Improve the proton conductive ability of film.Show as in system and utilization side heat: simplified cooling system; Can effectively utilize used heat; Reduce reforming system water vapour usage quantity.Along with the intensification of people to high temperature proton exchange film fuel cell understanding, the heat-stable proton exchange membrane of development of new is paid attention to by increasing research worker.
Summary of the invention
In order to develop high temperature proton exchange film fuel cell, the object of the present invention is to provide a kind of high temperature proton exchange film fuel cell composite membrane and preparation method thereof with widely-used temperature (0-200 ℃).
For achieving the above object, the technical solution used in the present invention is:
A kind of acid pickling macromolecule compound proton exchange membrane is meant and adopts phosphoric acid and/or the quaternised heat-proof macromolecule polymeric film of heteropolyacid submerged that the weight ratio of phosphoric acid and/or heteropolyacid and quaternised heat-proof macromolecule polymeric film can be 0.5-6: 1.
The weight ratio of described phosphoric acid and/or heteropolyacid and quaternised heat-proof macromolecule polymeric film is preferably 1-4: 1; Heteropolyacid is meant the H with proton exchange function
3BM
12O
40Compound, wherein, B=P, Si or As, M=Mo, W or V; The quaternary ammonium polymer monomer of the quaternised heat-proof macromolecule polymeric film of described formation should comprise following structure:
As: quaternized polyether-ether-ketone film, quaternized polysulfones ether ketone film, quaternized polyimide film, quaternized poly (ether sulfone) film, quaternized polysulfone membrane, quaternized poly quinoline film, quaternized poly-phosphine eyeball film or quaternized polysilane film.
The preparation method of acid pickling macromolecule compound proton exchange membrane can operate according to the following procedure,
A) quaternised heat-proof macromolecule polymeric film being immersed excessive weight concentration is in 10-98% (being preferably 50-80%) phosphoric acid and/or the heteropolyacid solution, leaves standstill 〉=5 minutes;
B) take out the attached acid of wiping remained on surface behind the film, obtain required compound proton exchange membrane.
Be soaked with quaternised heat-proof macromolecule polymeric film phosphoric acid or/temperature of heteropolyacid solution left standstill do not have particular requirement, phosphoric acid and/or heteropolyacid solution need not freeze and the evaporable state that do not seethe with excitement under all can; Under higher temperature, just leaving standstill of short period of time can reach needed compound proton exchange membrane; Under lower temperature, the time of leaving standstill will be grown.
The present invention has compared following advantage with existing material with technology:
1. the proton exchange ability of film is strong.The purpose that phosphoric acid and/or heteropolyacid are immersed in the present invention is to improve the proton conductivity of film, in the hope of reaching the requirement of PEMFC battery to film; The compound proton exchange membrane that utilizes preparation method proposed by the invention to make all has excellent proton exchange ability at low temperature and high temperature, and the use temperature of the proton exchange membrane that the present invention is prepared is 0-200 ℃, and it is wide to have the use temperature scope, and it is strong to lead the proton ability.
2. the good stability of film.A kind of polymkeric substance that can catch proton fast of quaternised heat-proof macromolecule polymeric film has good chemical stability and thermostability; The compound proton exchange membrane that utilizes preparation method proposed by the invention to make has good chemical stability (heat decomposition temperature>220 ℃) and good alcohol-rejecting ability.The prepared proton exchange membrane of the present invention all can be used in room temperature-200 ℃ scope, has use temperature widely.
3. preparation technology is simple, and cost is low.The present invention is immersed phosphoric acid and/or heteropolyacid with quaternised heat-proof macromolecule polymeric film, obtains compound proton exchange membrane.Compound proton exchange membrane preparation technology is simple, and the cost of material is low is easy to industrialization; Compound proton exchange membrane of the present invention can be used in the high temperature proton exchange film fuel cell (as: be with hydrogen fuel and be the high temperature proton exchange film fuel cell of raw material with methyl alcohol) and direct alcohol fuel battery, and it will promote the development of high temperature proton exchange film fuel cell.
Description of drawings
Fig. 1 soaks the H of the composite membrane of phosphoric acid for quaternised polyether-ether-ketone
2/ O
2The performance collection of illustrative plates of fuel cell.
Embodiment
Embodiment 1
It is in 10% phosphoric acid solution that quaternised poly (ether sulfone) film is immersed weight concentration.Under 25 ℃, left standstill 20 minutes.Wipe the acid on surface after the taking-up, obtain required compound proton exchange membrane.The phosphoric acid amount that film absorbs is 248% of a quaternised poly (ether sulfone) film weight.
Embodiment 2
It is in 98% phosphoric acid solution that quaternized polyimide film is immersed weight concentration.Under 50 ℃, left standstill 30 minutes, and wiped the acid on surface after the taking-up, obtain required compound proton exchange membrane.The phosphoric acid amount that film absorbs is 337% of a quaternized polyimide film weight.
Embodiment 3
It is in 98% phosphoric acid solution that quaternized poly quinoline film is at first immersed weight concentration.Under 50 ℃, left standstill 30 minutes, and wiped the acid on surface after the taking-up, and then immerse in 10% phospho-wolframic acid, under 90 ℃, left standstill 20 minutes, wipe the acid on surface after the taking-up, obtain required compound proton exchange membrane.The acid amount that film absorbs is 320% of a quaternized poly quinoline film weight.
Embodiment 4
In the first immersion of quaternized polysulfones ether ketone film 70% phospho-molybdic acid, under 90 ℃, left standstill 20 minutes, wipe the acid on surface after the taking-up, obtain required compound proton exchange membrane.The acid amount that film absorbs is 160% of a quaternized polysulfones ether ketone film weight.
Embodiment 5
It is in the 40% silicotungstic acid solution that quaternized polysilane film is at first immersed weight concentration.Under 70 ℃, left standstill 30 minutes, and wiped the acid on surface after the taking-up, and then immerse in 40% phosphoric acid, under 50 ℃, left standstill 20 minutes, wipe the acid on surface after the taking-up, obtain required compound proton exchange membrane.The acid amount that film absorbs is 320% of a quaternized polysilane film weight.
Embodiment 6
It is in the 40% silicotungstic acid solution that quaternized polysilane film is at first immersed weight concentration.Under 70 ℃, left standstill 30 minutes, and wiped the acid on surface after the taking-up, and then immerse in 40% phosphoric acid, under 50 ℃, left standstill 20 minutes, wipe the acid on surface after the taking-up, obtain required compound proton exchange membrane.The acid amount that film absorbs is 320% of a quaternized polysilane film weight.
Embodiment 7
It is in 40% phosphoric acid solution that quaternized polysulfones ketone film is at first immersed weight concentration.Under 90 ℃, left standstill 200 minutes, and wiped the acid on surface after the taking-up, obtain required compound proton exchange membrane.The acid amount that film absorbs is 260% of a quaternized polysulfones ketone film weight.
Embodiment 8
It is in the 40% silicon vanadic acid solution that quaternized poly-phosphine eyeball film is at first immersed weight concentration.Under 90 ℃, left standstill 200 minutes, and wiped the acid on surface after the taking-up, and then immerse in 40% phosphoric acid, under 30 ℃, left standstill 50 minutes, wipe the acid on surface after the taking-up, obtain required compound proton exchange membrane.The acid amount that film absorbs is 320% of a quaternized poly-phosphine eyeball film weight.
Embodiment 9
It is in the 10% arsenowolframic acid solution that quaternized polysilane film is at first immersed weight concentration.Under 70 ℃, left standstill 30 minutes, and wiped the acid on surface after the taking-up, and then immerse in 40% phosphoric acid, under 50 ℃, left standstill 10 minutes, wipe the acid on surface after the taking-up, obtain required compound proton exchange membrane.The acid amount that film absorbs is 120% of a quaternized polysilane film weight