Regulating the electronic state of Pt via architecting symbiotic oxide support for optimal alkaline hydrogen evolution reaction
Yuhua Liu, Wei Zhang, Qing Liang, Yong Gao, Xu Zou, Xinyan Zhou, Fuxi Liu, Kexin Song, Wenwen Li, Jiajun She, Xiyang Wang, Nailin Yue, Huiqi Wang, Jingye Chen, Aofei Wei, Kaiyu Yang, Zhongjun Chen, Weitao Zheng
Abstract
Optimization of the electronic structure of Pt δ+ 5 d orbitals by using a well–defined coordination environment to increase the efficiency of alkaline H 2 O dissociation kinetics remains challenging. Herein, TiO 2 quantum dots (QDs) were carefully introduced into a Pt/Co 3 O 4 system to form Pt/QDs/Co 3 O 4 , which created a pool of high–density Pt clusters anchored on an emerging symbiotic oxide surface. The strong interaction between QDs and Co 3 O 4 induced the redistribution of Pt 5 d orbital electrons. Spectroscopic characterization and theoretical calculations revealed that the resulting dual–active centers ( α –Pt–O–Co and β –Pt–O–Co) played a key role in balancing hydrogen adsorption and strengthening water dissociation. Therefore, the support effect of the symbiotic TiO 2 /Co 3 O 4 oxides resulted in the Pt/QDs/Co 3 O 4 catalyst having a mass activity 2.17 times higher than that of Pt/C at an overpotential of 200 mV. In addition, the Pt/QDs/Co 3 O 4 required only 1.78 V to reach an industrial–level current density of 500 mA cm −2 , and it achieved continuous robust operation for over 500 h in an anion exchange membrane water electrolyser. The results obtained after the extended synthesis of a Ru/QDs/Co 3 O 4 catalyst confirm the universality of the proposed support. This work sheds light on the surface activity of metals through an investigation of a support–facilitated design for efficient catalysts.