Relationship Between Oxygen-Containing Groups and Acidity of Graphene Oxide Supported Mn-Based SCR Catalysts and the Effects on the Catalytic Activity

Graphene oxide (GO) with abundant oxygen-containing groups was chosen as the support for the NH3-SCR catalysts. The as-prepared catalysts were systematically characterized to elucidate the effects of the surface properties and the morphological structure on catalytic activity by Raman, XPS, XRD, SEM, TEM, BET, NH3-TPD, and H-2-TPR. It was found that compared with widely researched Graphene (GR), abundant oxygen-containing groups on the surface of GO provided the load sites and further promoted the dispersion of active component, which indicating the much more active sites exposed and further the better catalytic activity shown. Furthermore, the oxygen-containing groups like hydroxyl (-OH) and carboxyl (-COOH) could provide some Bronsted acid sites. After the loading of MnOx, the degree of graphitization of GO increased sharply, indicating the better electron transport and strong chemical interaction between GO and MnOx. Furthermore, the best load amount was found and the acidity was the main reason for the optimalizing performance on Mn-5/GO at low temperature. Besides, not only large specific area, but also outstanding redox performance and high dispersion of active component all contributed to the excellent performance of Mn-5/GO. Over all, this work formulated the advantages of GO worked as the support for SCR catalysts and significantly extended the cognition of GO and the selection basis of supports for the low-temperature NH3-SCR reaction. Graphic abstract The abundant oxygen-containing groups on the GO surface promoted the dispersion of the active material (MnOx) and also provided some weak acid sites.