Host-guest chemistry of hybrid silicoaluminophosphates encapsulated Cu (II) complex: superior activity towards chemical CO2 capture
Authors :- Prajapati, R.; Paredi, P.; Das, S.; Tsunoji, N.; Tyagi, D.; Bhattacharyya, K.; Bandyopadhyay, R.; Bandyopadhyay, M.
Publication :- Fuel (Elsevier), Volume 407, Part D, 1 March 2026
Growing concerns over the upward trend of global warming, driven by human-induced CO2 emissions, are fuelling the advancement of carbon capture and storage (CCU) projects around the world. Investigating porous materials, their structure–activity relationship, leads to their application as heterogeneous catalysts. This work aims preparation of a unique hybrid silicoaluminophosphate (SAPO) microporous material with a modified core–shell structure by post-synthetic base functionalization, followed by copper complex grafting. A novel mixed ligand copper (II) complex comprising 2,9-dimethyl-1,10-phenanthroline and copper nitrate was synthesized and characterized by single crystal XRD. The mononuclear Cu-complex encapsulated hybrid silicoaluminophosphate catalyst was characterized by PXRD, N2 adsorption–desorption, FT-IR, TGA, NMR and SEM techniques. Additionally, XPS analyses of modified SAPO-34 and the Cu-complex revealed structural and electronic details of aluminium sites and copper species showing Cu+ binding with SAPO-34, which is essential for epichlorohydrin ring-opening, providing insights into CO2 utilization mechanisms. Catalytic activity of this hybrid material was compared with pure SAPO-34 and SAPO-5, functionalized-only materials and without catalyst. The hybrid materials demonstrated up to 96 % efficiency in CO2 utilization at low pressure and at optimum reaction conditions. The novelty of the work lies in the prepared copper (II) complex and its immobilization in microporous support for excellent catalytic activity in CO2 utilization using minimum amount of catalyst.