Investigating the platinum electrode surface during Kolbe electrolysis of acetic acid
Margot Olde Nordkamp, Talal Ashraf, Marco Altomare, Andrea Casanova Borca, Paolo Ghigna, Tatiana Priamushko, Serhiy Cherevko, Viktoriia A. Saveleva, Cesare Atzori, Alessandro Minguzzi, Xiufang He, Guido Mul, Bastian Mei
Abstract
Platinum is commonly applied as the anode material for Kolbe electrolysis of carboxylic acids thanks to its superior performance. Literature claims that the formation of a barrier layer on the Pt anode in carboxylic acid electrolyte suppresses the competing oxygen evolution and promotes anodic decarboxylation. In this work, we show by using a combination of complementary in-situ and ex-situ surface sensitive techniques, that the presence of acetate ions also prevents the formation of a passive oxide layer on the platinum surface at high anodic potentials. Furthermore, Pt dissolves actively under these conditions, challenging the technical implementation of Kolbe electrolysis. Future studies exploring the activity-structure-stability relation of Pt are required to increase the economic viability of Kolbe electrolysis.