Mechanochemical Route for Preparation of MFI-Type Zeolites Containing Highly Dispersed and Small Ce Species and Catalytic Application to Low-Temperature Oxidative Coupling of Methane
Mizuho Yabushita, Motohiro Yoshida, Ryota Osuga, Fumiya Muto, Shoji Iguchi, Shuhei Yasuda, Atsushi Neya, Mami Horie, Sachiko Maki, Kiyoshi Kanie, Ichiro Yamanaka, Toshiyuki Yokoi, Atsushi Muramatsu
Abstract
MFI-type zeolites containing Ce species were prepared by a mechanochemically assisted two-step method, where first an amorphous Si–Ce–O composite was produced via a mechanochemical reaction of SiO2 and CeO2 and then transformed into an MFI-type zeolite under hydrothermal conditions. The Ce species in this sample were more highly dispersed than those in the two control materials: a Ce-containing MFI-type zeolite synthesized via the conventional one-pot hydrothermal approach and Ce species simply deposited on silicalite-1. The highly dispersed and small Ce species in the zeolite exhibited a unique catalytic performance for the oxidative conversion of methane after the impregnation of Pd species, and the combination of Pd and Ce species produced ethane even at reaction temperatures as low as 100–300 °C.