Efficient methanol upcycling to ethylene glycol and glycolaldehyde via divergent C−C coupling synthesis

Direct photocatalytic conversion of methanol into high-value multi-carbon chemicals through precisely controlled C − C coupling represents an extremely appealing but challenging goal. Herein, we demonstrate the efficient photoredox-driven dehydrocoupling of methanol into divergent synthesis of ethylene glycol and glycolaldehyde concomitantly with H2 production by structural regulation of atomically dispersed Ni species. We showcase distinctly different reaction pathway for divergent C − C coupling of methanol over two types of atomically dispersed Ni cocatalyst-decorated SiO quantum dots, namely those with single Ni atoms (Ni1-SiO/SiO2) and Ni clusters (Nin-CdS/SiO2). The Ni1-CdS/SiO2 generates ethylene glycol with 90% selectivity by a radical homo-coupling pathway, whereas the Nin-CdS/SiO2 achieves 96% selectivity towards glycolaldehyde by a radical addition-elimination pathway. This work not only offers a fascinating nonpetroleum route for the divergent C–C coupling synthesis of ethylene glycol and glycolaldehyde but also underscores the broad vista of modulating non-selective radicals toward selective transformation of methanol into multi-carbon products. This study tailors atomically dispersed Ni species on SiO2-supported CdS quantum dots to enable efficient photoredox-driven C − C coupling of methanol for divergent synthesis of high-value C2 chemicals with concomitant H2 production.