Photoelectrocatalytic self-cross coupling enabling carbon chain elongation

Long-chain compounds constitute fundamental feedstocks in modern chemical industries. Conventional chain elongation processes, however, remain constrained by their dependency on noble-metal catalysts and harsh operational parameters. To establish green and efficient carbon chain elongation protocols, this study designs a photoelectrocatalytic (PEC) system, enabling radical-mediated self-cross-coupling reactions. The system exhibits PEC performance in upgrading C2 molecules to value-added long-chain C3 products, achieving total selectivity exceeding 50% with a production rate of 159.17 mmol m^-2 h^-1. Moreover, diverse C2-C6 polyol substrates can be elongated to carbon-chain derivatives, demonstrating universal chain-elongation capability. In situ spectroscopy captures the dynamic evolution of reaction intermediates and verifies the critical role of chlorine radicals in enhancing the generation rates of carbon-centered and hydroxyl radicals. This work not only provides a solar-driven cross-coupling mechanism but also pioneers a green chemical synthesis pathway for sustainable and advanced long-chain chemicals.