Sinter-Resistant Single Core PtNi Alloy@SiO₂ Channel (<i>d</i> ≈ 20 nm) Catalysts for Dry Reforming of Methane

The dry reforming of methane (DRM) can drive the green transformation of the chemical industry, achieving effective environmental protection. Designing Ni-based catalysts with high activity and sintering resistance is one of the key factors in the implementation of DRM technology. In this study, a tip-growth carbon nanotube template strategy was for the first time proposed to prepare a sinter-resistant single core PtNi alloy@SiO2 channel (d ≈ 20 nm) catalyst (PtNi@SiO2). At 550 °C, the CH4 and CO2 conversion of PtNi@SiO2 in DRM reaction reach up to 31.5 and 34.1%, respectively, and almost no sintering phenomenon is observed after 40 h stability test. The excellent catalytic performance could be ascribed to the unique single core confinement function and the PtNi alloy synergistic effect. The highly dispersed single core PtNi particles are difficult to agglomerate during DRM. Besides, the inner walls of the SiO2 pore channels can effectively restrict the migration and sintering of single core PtNi alloy particles, thereby leading to the excellent sintering resistance of PtNi@SiO2. Importantly, compared to pure Ni, the PtNi alloy can reduce the highest dissociation energy barriers of CH4 and CO2 by 0.6 and 0.2 eV, respectively, thereby increasing its dry reforming activity.