MCM-41 supported nickel-based bimetallic catalysts with superior stability during carbon dioxide reforming of methane: Effect of strong metal–support interaction

Abstract

Nickel-based bimetallic catalysts supported on MCM-41 mesoporous molecular sieves (Ni–Ti-, Ni–Mn-, and Ni–Zr–MCM-41) were prepared by direct hydrothermal synthesis. The catalytic properties were tested in methane reforming with CO 2. All Zr-promoted catalysts exhibited comparable or enhanced initial catalytic activity as compared to Ni–MCM-41. Adding Zr 4+ remarkably improved the long-term stability, whereas decreased lower initial activity and stability were observed for Ti- and Mn-modified catalysts. The addition of Zr 4+ enhanced the structural stability and the dispersion of active Ni sites. The strong anchoring effect of Zr 4+ and the partial activation of CO 2 by Zr 4+ contributed to the high catalytic activity and long-term stability. On the contrary, the decoration of Ni clusters with TiO x and MnO x species on Ni–Ti and Ni–Mn catalysts hindered the accessibility of Ni-active centers, thus decreasing their catalytic performance. The partial transformation of amorphous silica matrix into quartz and/or tridymite phases over Ni–Mn, Ni–Ti, and Ni–MCM-41 catalysts also played a negative role on their catalytic stability.