Cheng Han, Gui Renjie, Chen Chen, Liu Si, Cao Xuemin, Yin Yifan, Ma Ruize, Wang Wenjie, Zhou Tianpei, Zheng Xusheng, Chu Wangsheng, Xie Yi, Wu Changzheng
Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230029, China.
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China.
Natl Sci Rev. 2024 Jul 8;11(8):nwae233. doi: 10.1093/nsr/nwae233. eCollection 2024 Aug.
Platinum-based intermetallic compounds (IMCs) play a vital role as electrocatalysts in a range of energy and environmental technologies, such as proton exchange membrane fuel cells. However, the synthesis of IMCs necessitates recombination of ordered Pt-M metallic bonds with high temperature driving, which is generally accompanied by side effects for catalysts' structure and performance. In this work, we highlight that semimetal atoms can trigger covalent interactions to break the synthesis-temperature limitation of platinum-based intermetallic compounds and benefit fuel-cell electrocatalysis. Attributed to partial fillings of p-block in semimetal elements, the strong covalent interaction of d-p π backbonding can benefit the recombination of ordered Pt-M metallic bonds (PtGe, PtSb and PtTe) in the synthesis process. Moreover, this covalent interaction in metallic states can further promote both electron transport and orbital fillings of active sites in fuel cells. The semimetal-Pt IMCs were obtained with a temperature 300 K lower than that needed for the synthesis of metal-Pt intermetallic compounds and reached the highest CO-tolerant oxygen reduction activity (0.794 A mg at 0.9 V and 5.1% decay under CO poisoning) among reported electrocatalysts. We anticipate that semimetal-Pt IMCs will offer new insights for the rational design of advanced electrocatalysts for fuel cells.
铂基金属间化合物（IMCs）在一系列能源和环境技术中，如质子交换膜燃料电池，作为电催化剂发挥着至关重要的作用。然而，IMCs的合成需要在高温驱动下使有序的Pt-M金属键重新组合，这通常会对催化剂的结构和性能产生副作用。在这项工作中，我们强调半金属原子可以引发共价相互作用，打破铂基金属间化合物的合成温度限制，并有利于燃料电池的电催化。由于半金属元素p区的部分填充，d-p π反馈键的强共价相互作用有利于在合成过程中有序的Pt-M金属键（PtGe、PtSb和PtTe）的重新组合。此外，这种金属态的共价相互作用可以进一步促进燃料电池中活性位点的电子传输和轨道填充。半金属-Pt IMCs的合成温度比金属-Pt金属间化合物的合成温度低300 K，并且在已报道的电催化剂中达到了最高的抗CO氧还原活性（在0.9 V时为0.794 A mg，在CO中毒下衰减5.1%）。我们预计半金属-Pt IMCs将为燃料电池先进电催化剂的合理设计提供新的见解。
