Long-Chain Hydrocarbons from Nonthermal Plasma-Driven Biogas Upcycling.

The burgeoning necessity to discover new methodologies for the synthesis of long-chain hydrocarbons and oxygenates, independent of traditional reliance on high-temperature, high-pressure, and fossil fuel-based carbon, is increasingly urgent. In this context, we introduce a nonthermal plasma-based strategy for the initiation and propagation of long-chain carbon growth from biogas constituents (CO and CH). Utilizing a plasma reactor operating at atmospheric room temperature, our approach facilitates hydrocarbon chain growth up to C40 in the solid state (including oxygenated products), predominantly when CH exceeds CO in the feedstock. This synthesis is driven by the hydrogenation of CO and/or amalgamation of CH radicals. Global plasma chemistry modeling underscores the pivotal role of electron temperature and CH radical genesis, contingent upon varying CO/CH ratios in the plasma system. Concomitant with long-chain hydrocarbon production, the system also yields gaseous products, primarily syngas (H and CO), as well as liquid-phase alcohols and acids. Our finding demonstrates the feasibility of atmospheric room-temperature synthesis of long-chain hydrocarbons, with the potential for tuning the chain length based on the feed gas composition.