The development of methanol-tolerate oxygen reduction reaction(ORR)electrocatalysts is of special significance to direct methanol fuel cells system.Irdium is known for its better methanol tolerance than platinum and a...The development of methanol-tolerate oxygen reduction reaction(ORR)electrocatalysts is of special significance to direct methanol fuel cells system.Irdium is known for its better methanol tolerance than platinum and able to survive in harsh acidic environment.However,its activity is relatively low and thus the approach to improve Ir's ORR is desired.Herein,bimetallic Ir-Cu nanoparticles(NPs)with controllablc Ir/Cu compositions(ca.1:2 to 4:1,atomic ratio)are synthesized via a galvanic replacement-based chemical method.The as-synthesized Ir-Cu NPs are investigated as ORR catalysts after electrochemically leaching out the surface Cu and forming Ir-skinned structures.Around 2-to 3-fold enhancement in the intrinsic activity has been observed in these Ir-skinned Ir-Cu catalysts compared to Ir counterpart.The approach is demonstrated to be a promising way to prepare efficient Ir ORR catalysts and lower catalyst cost.展开更多
基金the Project of the Singapore Ministry of Education Tier 2(No.MOE2017-T2-1-009)the Singapore National Research Foundation Under Its Campus for Research Excellence and Technological Enterprise(CREATE)Programme。
文摘The development of methanol-tolerate oxygen reduction reaction(ORR)electrocatalysts is of special significance to direct methanol fuel cells system.Irdium is known for its better methanol tolerance than platinum and able to survive in harsh acidic environment.However,its activity is relatively low and thus the approach to improve Ir's ORR is desired.Herein,bimetallic Ir-Cu nanoparticles(NPs)with controllablc Ir/Cu compositions(ca.1:2 to 4:1,atomic ratio)are synthesized via a galvanic replacement-based chemical method.The as-synthesized Ir-Cu NPs are investigated as ORR catalysts after electrochemically leaching out the surface Cu and forming Ir-skinned structures.Around 2-to 3-fold enhancement in the intrinsic activity has been observed in these Ir-skinned Ir-Cu catalysts compared to Ir counterpart.The approach is demonstrated to be a promising way to prepare efficient Ir ORR catalysts and lower catalyst cost.
