A novel MnTi mixed oxide catalyst engineered by metal–organic framework precursor for enhancing NO_x removal performance

Abstract

In this research, MnTi metal-organic frameworks (MnTi-MOFs) were successfully prepared, and derived catalysts were innovatively applied to the removal of NO x by selective catalytic reduction with NH 3 (NH 3 -SCR). The test results show that the one-step controllable synthesis of MnTi-MOFs material is achieved through adjusting the Mn/Ti molar ratios and the proportion of metal to organic ligands, in which the ratio of organic ligands is vitally significant for the synthesis of MnTi-MOFs (MnTi-MOFs can only be synthesized with the ligand to metal molar ratio in the range of 3-4). Owing to the special heterogeneity of MOFs, the catalyst sample derived from the MnTi-MOFs precursor prepared with suitable raw material ratio exhibits the best SCR performance. Series of characterization analyses show that the catalysts derived from MOFs precursors with ordered lattice structure exhibit an appropriate surface chemical adsorption oxygen, an increased Mn 4+ /Mn n+ content, and enhanced acidity of the surface of the sample. This research affords an innovative method to the controllable preparation of dual metal MOFs and expands the development of catalysts in the field of low-temperature de-NO x .