Heterogeneous Catalysis with Metal-Containing Crystalline Porous Materials:Element-and Site-Specific Insights

Metal-containing crystalline porous materials(CPMs)are gaining popularity in heterogeneous catalysis because of their highly crystalline and porous systems,and their excellent chemical tunability.Modification of the metal species and framework structure permits them to have greater activity,selectivity,and stability over other materials.An in-depth understanding of the complex nature of metal active sites in CPMs is essential for revealing the structure-performance relationships and directing the rational design of such catalysts.Compared to conventional characterization techniques,the rapid development of X-ray absorption spectroscopy(XAS)has provided element-and site-specific deep insights into the electronic and structural information of metal species in CPMs.As such,this review begins by summarizing novel XAS techniques and analysis methods in accurately obtaining such data.Next,the combination of XAS with other high-level characterization methods into disclosing the configuration of active sites in metalcontaining CPMs is presented.Then,the utilization of theory-assisted XAS data analysis in examining complex metal-containing CPM catalysts is discussed.Afterwards,advanced in-situ/operando XAS studies into revealing the working sites in metal-containing CPMs under catalytic conditions are highlighted.We conclude by outlining the future challenges and prospects of XAS measurements,data analyses,and in-situ/operando setups in advancing the study of metal-in-CPM catalysts.