Excavated Rh nanobranches boost ethanol electro-oxidation

Direct ethanol fuel cells are a type of promising energy conversion device with high energy density, and their commercialization is still impeded by incomplete oxidation of ethanol on available electrocatalysts. Herein, a kind of novel excavated Rhodium (Rh) nanobranches constructed by ultrathin nanosheets with high-energy {110} facets and high surface area was successfully synthesized, which shows a high selectivity of complete oxidation ethanol to CO2 up to 15.8% (at 0.0 V vs Hg/HgO) in alkaline solution, outperforming currently reported monometallic electro-catalysts. The in situ Fourier transform infrared reflection spectroscopy and density function theory calculations demonstrated that the C-C bond cleavage of ethanol is very sensitive to the structure of Rh crystallites, and the unique {110} facets and excavated polyhedral morphology endow the Rh electro-catalysts with unexpected high selectivity, as well as high electro-catalytic activity and great structural stability. (C) 2018 Elsevier Ltd. All rights reserved.