Sn-based electrocatalysts have shown great potential in the future industrial application of CO2 electroreduction (CO2 ER) to C1 products due to their non-toxicity and low price. However, it is a great challenge to fabricate a Sn-based electrocatalytic system with high performance and stability. Herein, grafted pyridine was innovatively coupled with SnO2 to construct an organic-inorganic composite (SnO2 /Py-CNTO) for highly efficient CO2 ER. The detailed studies showed that pyridine and protonated pyridine coexist on the surface of SnO2 /Py-CNTO, and both play distinctive roles in promoting the selectivity of CO2 ER. Benefiting from the merits, SnO2 /Py-CNTO delivered an excellent faradaic efficiency (FE) of 96 % for CO2 ER at -1.29 VRHE where the HCOOH production with 85 % FE dominated, and good stability for 32 h electrolysis. The theoretical calculations showed that protonated pyridine not only facilitates the CO2 adsorption and HCOOH desorption, but also significantly reduces the limiting potential for the conversion of CO2 to HCOOH.
Keywords: CO2 electroreduction; SnO2 nanoparticles; electrocatalysis; grafted pyridine; synergistic effect.
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