Electrocatalysis of organics for electrolysis and/or fuel cells: Some thoughts on using the ratio of forward to backward peak current as a measure of electrocatalyst efficiency and/or poisoning

Abstract

In the current context of sustainability, the selective electrocatalytic transformation of biomass-derived organic substances into value-added products should offer vast design possibilities for power generation or the electrosynthesis of fuels and commodity chemicals. In this contribution, we have examined a number of concepts concerning the electrocatalysis of organic molecules for which noble metals cannot be excluded from the electrocatalyst composition without compromising the significant energy savings promised in electrolyzers (up to 50 % for H2 co-production compared with conventional water electrolysis). The widespread practice of using the ratio of forward peak current to backward peak current as a measure of activity, anti-poison capacity or removal of adsorbed poisons or intermediates is unsuitable based on voltammetry and spectroelectrochemical analysis.