质子交换膜燃料电池阳极抗CO毒化单原子催化剂的研究进展

Exploration of anode anti-CO poisoning in proton exchange membrane fuel cell

质子交换膜燃料电池在实现规模化应用前必须要处理好阳极CO毒化的问题.单原子催化剂作为当前催化领域的研究前沿和热点,在抗CO毒化领域的应用受到了广泛关注.本文从实现抗CO毒化的常用方法出发,简要介绍了CO氧化的机理和用于抗CO毒化的单原子Pt,Au和Rh等催化剂的研究进展,并展望了阳极抗CO毒化相关研究的发展方向.

As a feasible technical route to promote the global energy transition,hydrogen energy has gradually become a hot topic in the energy field.At present,the power density of the proton exchange membrane fuel cell(PEMFC)that uses hydrogen as fuel has reached the requirements of practical applications,but the commercialization of hydrogen fuel cell vehicles is restricted by the cost of hydrogen.Industrial by-product hydrogen,natural gas reforming hydrogen production can provide PEMFC with a large amount of low-cost hydrogen,but because the small amount of CO contained therein will significantly poison the anode catalyst of PEMFC,its adsorption on the surface of the catalyst will prevent the adsorption and desorption of hydrogen and hinder the catalytic oxidation of fuel.Therefore,anti-CO poisoning of anode is an unavoidable problem in the process of commercial application of PEMFC.The single-atom catalyst(SAC)is a new type of heterogeneous catalyst with atomically dispersed active centers.It has extremely high atom utilization and excellent reactivity and selectivity.With its excellent performance and low metal cost,SAC has injected strong kinetic energy into the development of the field of anti-CO poisoning.The CO poisoning resistance of PEMFC should essentially be started from the perspective of catalysts.Adopting various methods to promote the catalytic oxidation of CO by a single atom will be the main direction of future research.There are two main ideas for anti-CO poisoning of PEMFC.One is to purify hydrogen-rich gas to remove CO in H;in advance;the other is to prepare a new type of anti-CO poisoning electrocatalyst to oxidize CO or reduce the poisoning effect of CO.The above two anti-poisoning from the perspective of catalyst strategy is the current research hotspot.At present,it has been widely accepted that the CO oxidation reaction mechanism is mainly based on the MvK mechanism and the L-H mechanism.Under the acidic conditions related to PEMFC,the traditional anode anti-poisoning electrocatalyst catalyzes the CO oxidation following the L-H mechanism,and its CO resistance receptivity is usually attributed to electronic effects and dual-function mechanisms.In recent years,most reports on the application of SAC in CO poisoning are based on precious metals,such as Pt,Au,Pd,Ir,Rh and Ru,etc.We mainly discuss the above the research progress of precious metal SAC as CO preferential oxidation catalyst and electrocatalyst in the field of anti-CO poisoning,to help clarify the reaction mechanism,and to propose a promising SAC for future practical applications.