Perovskite Oxides as an Opportunity to Systematically Study the Electrooxidation of Alcohols and Polyols on Materials Based on Abundant Elements: Learning from the Experience Using Pure Metals and Metallic Oxides in Electrocatalysis

Thecost-effective production of green hydrogen is one of the mostimportant challenges for a sustainable energy transition. To decreasethe cost of the production of hydrogen through electrolysis, thereare several obstacles that must be overcome. For instance, more activeand stable anodes made of abundant and cheap materials will contributeto lowering capital and operational expenditure. It is well knownthat the oxidation of water requires high overpotentials, which isthe main limitation of the performance of the device. In this context,substituting the oxidation of water [oxygen evolution reaction (OER)]at the anode of electrolyzers by the oxidation of biomass-derivedsubstances contributes to the overall process by decreasing the powerinput of the devices and, in some cases, by producing value-addedchemicals. Herein, we revisited some of the most important fundamentalaspects of the electrooxidation of alcohols and polyols on metal-basedcatalysts, focusing on reaction descriptors. Then, we moved to theelectrooxidation of these molecules on metal oxides, revisiting someof the literature about their application in heterogeneous catalysisand for OER, to get insights about the relation of the structure ofthe materials and their activity. Due to the lack of fundamental knowledgeabout the electrooxidation of alcohols and polyols on metallic oxidesand to the vast literature about the use of perovskite oxides forOER, we propose to start systematic studies using perovskite oxidesfor the electrooxidation of alcohols and polyols. Consequently, wepresented results for LaCoO3, LaFeO3, LaMnO3, and LaNiO3 and proposed a mechanism for the electrooxidationof glycerol based on the formation and reactivity of MOH(O) species.We believe that fundamental and systematic studies on this topic wouldpermit the establishment of reaction descriptors, speeding up thesearch for suitable materials for this reaction and paving the wayfor more cost-effective production of green hydrogen.

Automated summary

The cost-effective production of green hydrogen is a significant challenge for sustainable energy transition. Overcoming obstacles to decrease the cost of hydrogen production through electrolysis, such as developing more active and stable anodes made of abundant and cheap materials. The substitution of biomass-derived substances for the oxidation of water at the anode of electrolyzers can decrease power input and potentially generate value-added chemicals.