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 (Ni_n-CdS/SiO₂). The Ni₁-CdS/SiO₂ generates ethylene glycol with 90% selectivity by a radical homo-coupling pathway, whereas the Ni_n-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.