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

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.