Supported ruthenium carbido-cluster catalysts for the catalytic removal of nitrogen monoxide and sulfur dioxide: the preparation process monitored by sulfur K-edge X-ray absorption near-edge structure

摘要

The preparation process of ruthenium carbido-cluster catalysts for the reduction of sulfur dioxide was traced by means of sulfur K-edge X-ray absorption near-edge structure (XANES). During the activation process, a pair of peaks at 2472.5 ― 2472.8 and 2482.7 ―2482.8 eV appeared. The pair was ascribed to the RuS_x phase. Once the catalysts were activated at 503 ― 573 K, another pair of peaks at 2474.2 and 2479.2 eV appeared. The pair was assigned to the π~* and σ~* transition peaks, respectively, of adsorbed SO_2 molecules on the catalyst surface.