Long-term stable catalyst for dry reforming of Methane: Ni-Nanocluster embedded in silica

Dry reforming of methane (DRM) is a fascinating catalysis to convert greenhouse gases into valuable syngas; however, the catalyst deactivation due to coking and sintering has posed a significant obstacle to practical use. Here, we introduce a novel synthetic approach for creating Ni nanoclusters (∼2 nm) embedded inside silica (NiES), without using any catalytic metal promoters. Compared to conventional Ni-SiO₂ catalysts, the NiES catalyst could fully utilize unique Ni-O-Si bonding within a bimodal silica matrix. This leads to exceptional reactivity and long-term stability for DRM without noticeable deactivation over 500 h of operations. Notably, characterizations revealed that Ni nanoclusters maintained their particle size even after this extended operation, significantly contributing to their resistance against carbon coking. These Ni clusters appeared to efficiently promote CH₄ decomposition, while the continuously regenerated OH groups from dissociative adsorption of CO₂ assisted in oxidizing carbon species. This study will substantially contribute to the swift implementation of the catalytic DRM process.