Highly Selective Nonoxidative Coupling of Methane over Pt-Bi Bimetallic Catalysts

There is widespread interest in converting methane, primary component of natural gas and shale gas, into valuable chemicals. As an important direct methane transformation technique, despite extensive research conducted for decades, oxidative coupling of methane (OCM) remains industrially uneconomical owing to low selectivity toward valuable target products (C-2 species, ethane/ethylene). In the present work, we describe that ZSM-5 zeolite supported bimetallic Pt-Bi catalysts stably and selectively convert methane to C-2 species with high carbon selectivity (> 90%) at relatively moderate temperatures (600-700 degrees C). On the basis of experimental observations, it is proposed that the surface Pt in the catalysts functions as the active site for methane activation, while Bi addition as promoter plays an important role in C-2 species formation and catalyst stability.