Tuning Mass Transport in Electrocatalysis Down to Sub‐5 nm through Nanoscale Grade Separation
Zhenhui Liu, Yue Du, Ruohan Yu, Mingbo Zheng, Rui Hu, Jingsong Wu, Yongyao Xia, Zechao Zhuang, Dingsheng Wang
Abstract
Abstract Nano and single‐atom catalysis open new possibilities of producing green hydrogen (H 2 ) by water electrolysis. However, for the hydrogen evolution reaction (HER) which occurs at a characteristic reaction rate proportional to the potential, the fast generation of H 2 nanobubbles at atomic‐scale interfaces often leads to the blockage of active sites. Herein, a nanoscale grade‐separation strategy is proposed to tackle mass‐transport problem by utilizing ordered three‐dimensional (3 d ) interconnected sub‐5 nm pores. The results reveal that 3 d criss‐crossing mesopores with grade separation allow efficient diffusion of H 2 bubbles along the interconnected channels. After the support of ultrafine ruthenium (Ru), the 3 d mesopores are on a superior level to two‐dimensional system at maximizing the catalyst performance and the obtained Ru catalyst outperforms most of the other HER catalysts. This work provides a potential route to fine‐tuning few‐nanometer mass transport during water electrolysis.