Producing ultrastable Ni-ZrO2 nanoshell catalysts for dry reforming of methane by flame synthesis and Ni exsolution

Commercial dry reforming of methane (DRM) is limited by catalyst deactivation through metal sintering and coking. New catalyst syn-thesis methods are needed to overcome such challenges. Here, we report a unique flame aerosol synthesis and exsolution method for producing hollow Ni-Zr oxide nanoshells as a highly stable and effi-cient DRM catalyst. This process incorporates immiscible elements into single-phase hollow nanoshells by rapid particle formation and quenching. Ni nanoparticles are then uniformly exsolved from the metastable solid solution to provide strong metal-support inter-actions that limit metal sintering. Rapid synthesis under reducing conditions produces oxygen vacancies in ZrO2 that favor carbon removal during the DRM reaction. As a result, our catalyst main-tained 98% CH4 conversion for more than 500 h, without sintering or coking, dramatically outperforming conventional catalysts. This method of metastable solid solution nanoshell formation followed by active site exsolution could provide durable catalysts for many high-temperature reactions.

Automated summary

This study reports a new catalyst synthesis method for producing stable and efficient hollow Ni-Zr oxide nanoshells as a DRM catalyst using flame aerosol synthesis and exsolution. The incorporation of immiscible elements into single-phase hollow nanoshells and the formation of oxygen vacancies in ZrO2 contribute to the catalyst's stability and activity during the DRM process.