Proton exchange membrane fuel cells(PEMFCs)are becoming a major part of a greener and more sustainable future.However,the costs of high-purity hydrogen and noble metal catalysts alongside the complexity of the PEMFC s...Proton exchange membrane fuel cells(PEMFCs)are becoming a major part of a greener and more sustainable future.However,the costs of high-purity hydrogen and noble metal catalysts alongside the complexity of the PEMFC system severely hamper their commercialization.Operating PEMFCs at high temperatures(HT-PEMFCs,above 120℃)brings several advantages,such as increased tolerance to contaminants,more affordable catalysts,and operations without liquid water,hence considerably simplifying the system.While recent progresses in proton exchange mem-branes for HT-PEMFCs have made this technology more viable,the HT-PEMFC viscous acid electrolyte lowers the active site utilization by unevenly diffusing into the catalyst layer while it acutely poisons the catalytic sites.In recent years,the synthesis of platinum group metal(PGM)and PGM-free catalysts with higher acid tolerance and phosphate-promoted oxygen reduction reaction,in conjunction with the design of catalyst layers with improved acid distribution and more triple-phase boundaries,has provided great opportunities for more efficient HT-PEMFCs.The progress in these two interconnected fields is reviewed here,with recommendations for the most promising routes worthy of further investigation.Using these approaches,the performance and durability of HT-PEMFCs will be significantly improved.展开更多
基金C.Zhao thanks the Australian Research Council(LP200100255,DP229103294,IC200100023)Y.Cheng thanks the National Natural Science Foundation of China(U19A2017,22272206)+1 种基金Natural Science Foundation of Hunan Province(S2021JJMSXM3153)Q.Meyer acknowledges T.Budd for the preparation of Fig.20 and K.Dastafkan and K.Ching for proofreading the manuscript.
文摘Proton exchange membrane fuel cells(PEMFCs)are becoming a major part of a greener and more sustainable future.However,the costs of high-purity hydrogen and noble metal catalysts alongside the complexity of the PEMFC system severely hamper their commercialization.Operating PEMFCs at high temperatures(HT-PEMFCs,above 120℃)brings several advantages,such as increased tolerance to contaminants,more affordable catalysts,and operations without liquid water,hence considerably simplifying the system.While recent progresses in proton exchange mem-branes for HT-PEMFCs have made this technology more viable,the HT-PEMFC viscous acid electrolyte lowers the active site utilization by unevenly diffusing into the catalyst layer while it acutely poisons the catalytic sites.In recent years,the synthesis of platinum group metal(PGM)and PGM-free catalysts with higher acid tolerance and phosphate-promoted oxygen reduction reaction,in conjunction with the design of catalyst layers with improved acid distribution and more triple-phase boundaries,has provided great opportunities for more efficient HT-PEMFCs.The progress in these two interconnected fields is reviewed here,with recommendations for the most promising routes worthy of further investigation.Using these approaches,the performance and durability of HT-PEMFCs will be significantly improved.
