Ultrasound-driven triphasic contact-electro-catalytic CO2 reduction to methanol

Abstract

Converting carbon dioxide (CO₂) into high-value fuels and chemicals via catalytic technologies has emerged as a leading strategy for achieving carbon cycling and mitigating the energy crisis. However, traditional electrocatalytic processes typically rely on external power sources and noble metal catalysts, posing challenges of high cost and large energy consumption. This work reports a novel contact-electrification-based catalytic strategy using a polyimide (PI) aerogel, a non-metallic catalyst, for the direct catalytic conversion of CO₂ and achieving an ultra-high methanol selectivity of 93.6%. The method leverages surface charges and a localized electric field generated by ultrasound-driven triboelectric material contact–separation, combined with a CO₂-adsorbed imide functional group on the PI aerogel, to realize efficient CO₂-to-methanol synthesis without external power or metal catalysts. Mechanistic studies reveal that the PI aerogel exhibits excellent contact-electrification properties and the imide functional group is capable of adsorbing CO₂. As the core component of the contact-electrification catalytic layer, the PI aerogel not only reduces reaction energy consumption but also forms a triphasic catalytic structure by connecting the gas–liquid phases, significantly enhancing reaction efficiency. This study provides a new paradigm for low-energy, green conversion of CO₂ to high-value chemicals.