Investigation of the Effect of Zeolite Supports and the Role of W-Species for One-Pot Catalytic Conversion of Cellulose to Ethylene Glycol: Theoretical & Experimental Studies.

Endeavors were made to study the influence of various zeolite (HY, NaY, NaZSM-5 and HZSM-5) supports with (Al)-Ni-W metal combination catalysts for the ethylene glycol (EG) production, selectively from cellulose. From the experimental results ZSM-5 (NaZSM-5/73.3% & HZSM-5/67.7%) support is superior over HY & NaY support in selective EG production from cellulose. It was understood that W- species with oxygen vacancies (WO 3-x , XPS analysis) plays an important role in producing the glycolaldehyde (GA) intermediate (via C-C cleavages), which on hydrogenation over Ni- sites selectively produce EG. Further, the studies based on the Density Functional Theory (DFT) were conducted to substantiate the involvement of the WO 3-x species in the reaction. The adsorption energies and structural changes establish that the C 2 -C 3 bond of the glucose elongates and thereby activates on adsorbing to WO 3-x sites supporting the formation of GA. Activation of GA on Ni- sites is distinguished by an increase of 0.1 Å in C=O bond length, which facilitates the hydrogenation of C=O resulting in EG. The reaction pathway is explained through an analysis of CDD and DOS.