Pyridine Grafted on SnO -Loaded Carbon Nanotubes Acting as Cocatalyst for Highly Efficient Electroreduction of CO.

Sn-based electrocatalysts have shown great potential in the future industrial application of CO electroreduction (CO ER) to C 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 SnO to construct an organic-inorganic composite (SnO /Py-CNTO) for highly efficient CO ER. The detailed studies showed that pyridine and protonated pyridine coexist on the surface of SnO /Py-CNTO, and both play distinctive roles in promoting the selectivity of CO ER. Benefiting from the merits, SnO /Py-CNTO delivered an excellent faradaic efficiency (FE) of 96 % for CO ER at -1.29 V 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 CO adsorption and HCOOH desorption, but also significantly reduces the limiting potential for the conversion of CO to HCOOH.