The Electronic Metal-Support Interaction Directing the Design of Single Atomic Site Catalysts: Achieving High Efficiency Towards Hydrogen Evolution.

ABSTRACT

It is still of great difficulty to develop the non-platinum catalyst with high catalytic efficiency towards hydrogen evolution reaction via the strategies till now. Therefore, it is necessary to develop the new methods of catalyst designing. Here, we put forward the catalyst designed by the electronic metal-support interaction (EMSI), which is demonstrated to be a reliable strategy to find out the high-efficiency catalyst. We carried out the density functional theory calculation first to design the proper EMSI of the catalyst. We applied the model of M1-M2-X (X=C, N, O) during the calculation. Among the catalysts we chose, the EMSI of Rh1TiC, with the active sites of Rh1-Ti2C2, is found to be the most proper one for HER. The electrochemical experiment further demonstrated the feasibility of the EMSI strategy. The single atomic site catalyst of Rh1-TiC exhibits higher catalytic efficiency than that of state-of-art Pt/C. It achieves a small overpotential of 22 mV and 86 mV at the at the current density of 10 mA cm-2 and 100 mA cm-2 in acid media, with a Tafel slope of 25 mV dec-1 and a mass activity of 54403.9 mA cm-2 mgRh -1 (vs. 192.2 mA cm-2 mgPt -1 of Pt/C). Besides, it also shows appealing advantage in energy saving compared with Pt/C (≈20 % electricity consuming decrease at 2 kA m-2 ) Therefore, we believe that the strategy of regulating EMSI can act as a possible way for achieving the high catalytic efficiency on the next step of SACs.