Research On Modified Antimony Tin Oxide Supporting Material As Anode Pt-based Catalyst For Direct Methanol Fuel Cell

Direct methanol fuel cell(DMFC)is a kind of energy conversion device that directly converts chemical energy into high-efficiency,environmentally-friendly energy.It has a good application prospect in the fields of power batteries and other fields of new energy vehicles.At present,as the only commercially available Pt/C catalyst,the catalytic activity is not high and the stability is not good,which hinders its further application.Certain metal oxides have stronger acid stability and mechanical strength than carbon materials,and to a certain extent have a strong metal-support interaction(SMSI)with Pt,which is considered as a favorable alternative to carbon materials.However,the electrochemical conductivity of metal oxides is not good,which has a great influence on the performance of the catalysts.Therefore,the metal oxides need to be used as catalysts after being modified.In this paper,a carbon-coated antimony tin oxide(ATO)carrier material was prepared by plasma-enhanced chemical vapor deposition(PECVD)method,and a Pt-based catalyst was prepared by a microwave-assisted ethylene glycol method.The carbon-coated antimony tin oxide ATO-C was prepared by PECVD and Pt/ATOC catalyst was prepared.The crystal structure and elemental composition of Pt/ATO-C were studied by XRD and EDX.The results showed that there are face-centered cubic Pt and cassiterite-like Sn O2 in the catalyst,and carbon is present in the catalyst;XPS was used to study Pt/ The surface elemental composition and state of ATO-C showed that there was a metal-support interaction between Pt and ATO.HRTEM results showed that Pt(111)crystal facets with lattice spacing of 0.221 nm and Sn O2(110)crystal faces with lattice spacing of 0.331 nm existed in Pt/ATO-C.The surface of ATO particles was coated with a layer of amorphous carbon.Platinum particles are uniformly deposited at the interface between carbon and ATO.The three factors of reaction time,reaction temperature and reactant concentration were optimized to improve the dispersion of platinum.Electrochemical tests showed that the amount of acetylene and argon introduced at 400 °C was 10 sccm,and the catalytic activity of the methanol oxidation reaction(MOR)of the catalyst after the platinum-supported catalyst was 90 min was the best.Commercial Pt/C is 2 times more stable than commercial Pt/C,and the MOR activity and stability of the prepared catalyst are higher than those of ATO directly loaded Pt catalyst.Introducing heteroelement N in ATO-C carrier to investigate its effect on catalyst performance.Firstly,ATO was mixed with urea and then sintered in vacuum to introduce N element.Then carbon was coated by PECVD to explore the reaction time on the catalyst.The impact of performance.The XPS results show that there are two kinds of doping of N in ATO-N-C,which are the oxygen ions that replaced Sn O2 and the gaps that enter Sn O2.Compared to Pt/ATO-C,Pt/ATO-N-C has a stronger interaction between Pt and the carrier.Electrochemical tests showed that the methanol oxidation activity of the catalyst was best at the reaction time of 90 min,and its stability and anti-poisoning ability were the strongest.Compared with Pt/ATO-C,the stability and anti-poisoning ability of Pt/ATO-N-C are greatly improved.