Steering the reaction pathway of syngas-to-light olefins with coordination unsaturated sites of ZnGaOx spinel

Significant progress has been demonstrated in the development of bifunctional oxide-zeolite catalyst concept to tackle the selectivity challenge in syngas chemistry. Despite general recognition on the importance of defect sites of metal oxides for CO/H-2 activation, the actual structure and catalytic roles are far from being well understood. We demonstrate here that syngas conversion can be steered along a highly active and selective pathway towards light olefins via ketene-acetate (acetyl) intermediates by the surface with coordination unsaturated metal species, oxygen vacancies and zinc vacancies over ZnGaOx spinel-SAPO-34 composites. It gives 75.6% light-olefins selectivity and 49.5% CO conversion. By contrast, spinel-SAPO-34 containing only a small amount of oxygen vacancies and zinc vacancies gives only 14.9% light olefins selectivity at 6.6% CO conversion under the same condition. These findings reveal the importance to tailor the structure of metal oxides with coordination unsaturated metal sites/oxygen vacancies in selectivity control within the oxide-zeolite framework for syngas conversion and being anticipated also for CO2 hydrogenation. Great progress has been made in the development of bifunctional oxide-zeolite catalysts to tackle the selectivity challenge in syngas chemistry. Here the authors show syngas conversion can be steered along a highly active and selective pathway towards light olefins via ketene acetate (acetyl) intermediates.

Automated summary

Significant progress has been made in the development of bifunctional oxide-zeolite catalysts to tackle the selectivity challenge in syngas chemistry. Syngas conversion can be steered towards light olefins via ketene acetate intermediates by utilizing the surface with coordination unsaturated metal species, oxygen vacancies, and zinc vacancies.