MOF-derived SN Co-doped carbon supported small-sized Ni nanoparticles for efficient CO2 reduction to CO

The Ni@SNC catalyst was prepared through a two-step pyrolysis-solvothermal method. • Sulfur species selectively etched amorphous carbon layers, exposing more active sites during doping. • Sulfur, as a doping atom, modulated the electronic structure of the active sites and enhanced the CO 2 RR performance. • The Ni@SNC catalyst achieved a maximum FE CO of 94.6%, with a current density of 13.4 mA cm -2 at this point. Utilizing renewable energy to catalyze the reduction of CO 2 into diverse high-value products represents an effective pathway for mitigating carbon emissions. Nickel-based catalysts benefit from natural abundance and low cost. Moreover, their CO 2 activation capability and *CO desorption characteristics can be optimized through rational structural design to modulate the adsorption energy of reaction intermediates. These properties make them viable alternatives to noble metal catalysts. In this study, a two-step method termed “pyrolysis-doping” was employed to synthesize the Ni@SNC catalyst, which consists of small-sized Ni nanoparticles supported on S N co-doped carbon, facilitating efficient electrocatalytic CO 2 reduction reaction (CO 2 RR). In the Ni@SNC structure, the coordination of surface Ni nanoparticles with N generates active sites, while S doping modulates the electronic state of these sites to optimize the adsorption of *COOH and the desorption of *CO. Performance tests indicated that Ni@SNC achieved a maximum CO Faradaic efficiency (FE CO ) of 94.6% at −0.9 V (vs. RHE), with a corresponding CO partial current density (j CO ) of 13.4 mA cm −2 , while exhibiting excellent stability during an extended electrolysis. Various characterizations and experiments have shown that S doping selectively etched the carbon layer, thereby increasing the electrochemically active area (ECSA). Furthermore, S doping modulated the electronic configuration of Ni N sites, enhancing the balance between adsorption and desorption of reaction intermediates. This work thus provides a new design method for creating efficient and stable non-precious metal CO 2 reduction catalysts. Download: Download high-res image (149KB) Download: Download full-size image