Ethanol Electrooxidation on Rhodium–Lead Catalysts in Alkaline Media: High Mass Activity, Long‐Term Durability, and Considerable CO2 Selectivity

Rhodium (Rh)‐based catalysts may solve the long‐standing inefficient oxidation of ethanol for direct ethanol fuel cells (DEFCs); however, the performance of ethanol oxidation reaction (EOR) on existing Rh‐based catalysts are far limited. Herein, the Rh–Pb catalysts are synthesized by building Pb and Pb oxide around Rh nanodomain, which shows highly efficient splitting CC bond and facile further oxidation of as‐generated C1 intermediates (COad and CHx fragments). It exhibits an ever‐highest EOR peak mass activity of ≈2636 mA mg−1Rh among Rh‐based catalysts in alkaline media. Meanwhile, its anodic current remains ≈50% even after a 4 h durability test at 0.53 V versus RHE. As for the C1‐pathway selectivity, in situ infrared adsorption spectral (IRAS) results demonstrate that it could significantly improve the production of CO2. More directly, the apparent faraday efficiency of EOR C1 pathway is estimated to be as high as 20% (at 0.53 V versus RHE). This Rh–Pb catalyst could hold great promise for developing the commercial DEFCs. The Rh–Pb bifunctional catalysts efficiently break ethanol CC bond at Rh domains and further quickly oxidize COad and CHx intermediates by OHad species provided by Pb and/or Pb oxide, thus exhibiting a superior ethanol electrooxidation activity of ≈2636 mA mg−1Rh in alkaline media and an apparent C1 pathway faraday efficiency up to 20%.