Hydrogen Spillover-Mediated Spatial Decoupling Process Boosts Syngas Conversion to Higher Oxygenates

The direct conversion of syngas to higher oxygenates presents a fundamental challenge in simultaneously achieving high CO conversion, superior oxygenate selectivity, and minimal undesired C 1 byproducts. Here, we develop a series of multifunctional Cu x Pd 1 /SiO 2 |CoMn catalysts with granule stacking architecture, which overcome the challenge by precisely controlling the spatial arrangement of active sites and the intermediate transport pathway. Systematic optimization reveals a distinct volcano-shaped relationship on Pd loadings, with the Cu 28 Pd 1 /SiO 2 |CoMn composite emerging as the optimal candidate. Such a catalyst achieves an exceptional oxygenates molar selectivity of 44.4% (C 2+ OH/ROH = 95.4%) while maintaining low C 1 products (6.4% CO 2 and 5.7% CH 4 ) at considerable 27.3% CO conversion. Mechanistic studies reveal that the breakthrough stems from precise control of spatial intimacy of functional components, optimized mass balance between CH x O* and CH x *, and isolated Pd atom-mediated hydrogen spillover effects. Based on spectroscopic evidence with theoretical calculations, we propose a synergistic catalytic system wherein PdCu single-atom alloys facilitate H 2 activation and CH x O* formation through hydrogen spillover, while Co 0 -Co 2 C interfaces produce abundant CH x * species. The synergistic interaction enables the migration of CH x O* intermediates from single-atom alloy sites to Co 0 -Co 2 C interfaces, where they undergo further insertion into CH x * species, ultimately leading to hydrogenation and formation of higher oxygenates.