Improved carbonate formation from ethanol oxidation on nickel supported Pt-Rh electrode in alkaline medium at room temperature

摘要

In search for catalysts capable to oxidize small alcohols completely to CO32- in alkali, a few nickel supported platinum-rhodium (Pt-Rh) binary electrodes of varying mutual composition have been constructed by galvanostatic co-deposition of Pt-Rh on Ni support from suitable precursors' solutions. The co-deposited particles are found to lie in the nano-size domain by electron microscopy. Catalyst with approximately 35 atom% of Rh shows the highest electrocatalytic activity among the various compositions of the binary Ni/PtRh catalyst system studied for anodic oxidation of ethanol. Ex-situ FTIR studies show that molar ratio of the two products CO32- and CH3COO- in sequence, is increased on increasing the content of Rh in the binary deposit. Extended studies of ethanol, acetaldehyde and acetate at low concentrations reveal that electrochemically produced M-OH is responsible for chemical oxidations of organic fuels and related intermediates. The results lead to develop a proposed mechanism for the reaction. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.