低温抗SO2铈基脱硝催化剂的低配位表面硫酸盐调控机制

氨选择性催化还原是目前最有效的烟气脱硝技术。CeO2基催化剂具有较宽的活性温度窗口和良好的高温N2选择性，被认为是商业V2O5基催化剂最具潜力的替代者。然而CeO2在SO2存在下容易发生硫化，CeO2基催化剂在含硫烟气中易中毒失活。本项目以提高传统CeO2/TiO2催化剂的低温抗硫性能为目标，采用“偶联剂辅助一步自组装”的催化功能化手段在TiO2载体上原位构筑具有短程有序Ce-O-M配位结构的金属氧化物催化剂。在SO2存在时，Ce-O-M/TiO2催化剂的Ce位点硫化后生成低配位的表面硫酸盐物种，未配位饱和的Ce位点可以吸附与活化NOx，实现NOx的高效活化与转化。此外表面硫酸盐物种的生成抑制了硫酸氢氨的沉积，确保反应分子可以在Ce-O-M催化界面上进行吸附与活化，实现高抗硫活性。通过本项目的实施，为高性能抗硫脱硝催化剂的结构设计和催化理论奠定科学基础。

Ammonia selective catalytic reduction is the most effective technology for NOx removal. CeO2-based catalysts are considered to be the most promising alternative to commercial V2O5-based catalysts because of their wide active temperature window and good N2 selectivity at high temperatures. However, CeO2 is sulfated easily in the presence of SO2, and CeO2-based catalysts are prone to be deactivated in SO2-containing flue gas. This project aims to improve the low-temperature SO2 resistance of traditional CeO2/TiO2 catalysts. Via the catalytic functionalization method of "coupling agent assisted one-step self-assembly", the Ce-O-M metal oxide catalysts with specific coordination structure and short-range order structure were in situ constructed on TiO2 support. In the presence of SO2, the Ce sites of Ce-O-M/TiO2 catalysts were sulfated to generate low coordination surface sulfate species, and the uncoordinated Ce sites could adsorb and activate NOx to realize the efficient catalytic abatement of NOx. In addition, the formation of sulfate species on the surface inhibited the deposition of ammonia bisulfate, which enable the reaction molecules can be adsorbed and activated on the Ce-O-M catalytic interface, thus achieving high SO2 resistant activity. Through the implementation of this project, it lays a scientific foundation for the structure design and catalysis theory of high-performance SO2-tolerant denitration catalyst.