Green Pathway for Upscaling CO2 and H2O Conversion via Synergizing Nonthermal Plasma with Biochar

Abstract

The conversion of CO₂ and H₂O into syngas by plasma is a desirable route for utilization of waste resources, energy conversion, and storage. However, it remains a great challenge to acquire satisfying conversion performance for an environmentally friendly and upscaling application. In this work, we propose a green strategy of synergizing nonthermal plasma with biochar for efficient conversion of high-flow CO₂–H₂O and reveal the reaction kinetics. Specifically, this work makes a breakthrough in that we achieve an energy efficiency of 23.6% at high flow rate (2000 mL/min) and H₂O content (50%), significantly outperforming other plasma reactors for CO₂–H₂O conversion. We find that the biochar surface reaction driven by plasma is the key for enhancing CO₂–H₂O conversion, where biochar reacts with OH and O radicals and suppresses recombination reactions of products, thus mitigating the quenching effect of H₂O. This work innovatively scales up CO₂–H₂O conversion, paving an avenue for its industrial application.