Electroreforming injects a new life into solid waste

Abstract

The drive to upgrade the system capacity for renewable electricity, coupled with relieving our reliance on the finite fossil resources, promotes the exploration for economically competitive and environmentally friendly technologies that can steer the conversion of the renewable feedstocks into fuels, chemicals, and materials. An appealing remedy is to utilize ubiquitous solid waste (e.g., biomass and plastics) as platform precursors to synthesize valuable chemicals used globally on a daily basis. Although the defined functionality of biomass differs from that of plastics, they share considerable structural similarities in terms of the polymeric nature and the type of bonds connecting the constituent monomers, thereby establishing an intimate correlation between their valorization routes. Electroreforming methodology towards upgrading of biomass and plastic wastes into commodity chemicals coupled with hydrogen evolution is thus viable and meanwhile remains intriguing. In this review, we draw parallels between electrochemical valorization of biomass and plastics, with a focus on elucidating the state-of-the-art catalysts for each documented reaction and evaluating their corresponding techno-economy. In parallel, the pretreatment methodologies for raw solid waste and the progress in computational simulations and operando spectroscopies are reviewed in detail. We conclude with a comprehensive discussion of the emerging challenges for catalyst and reactor optimization, large-scale operation, and technology flexibility and compatibility.