Substantially Stabilized Superacid Incorporated SBA-15 with Calcium Bridging for Selective Esterification of Glycerol

Malaysian Technical Universities Conference on Engineering and Technology 2017

Hoo, P.Y.^1 ; Abdullah, A.Z.^2 ; Shuit, S.H.^1 ; Teoh, Y.P.^1 ; Ng, Q.H.^1 ; Kunasundari, B.^1

Department of Chemical Engineering Technology, Faculty of Engineering Technology, Universiti Malaysia Perlis (UniMAP), Kampus UniCITI Alam, Sungai Chuchuh, Padang Besar, Perlis

02100, Malaysia^1

School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, Seri Ampangan, Nibong Tebal, Pulau Pinang

14300, Malaysia^2

关键词: 12-tungstophosphoric acid;    Acidity properties;    Characterization methods;    Functionalizations;    Heterogeneous catalyst;    Modification methods;    Modified catalysts;    Strong interaction;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/318/1/012007/pdf
DOI  :  10.1088/1757-899X/318/1/012007

来源: IOP

【 摘 要 】

The exploitation of the super acidity of heteropolyacids incorporated heterogeneous catalysts was only feasible if the heterogeneity of these catalysts was assured. To maintain the catalyst heterogeneity in polar medium, a novel two-step modification method was proposed to synthesize the highly active, yet stable heterogeneous catalyst, catered for selective esterification of monoglyceride. The surficial, structural and acidity properties of the modified catalysts were investigated via crucial characterization methods (N2BET, HRTEM, and FTIR). The collective evidences verified the predicted formation of calcium oxides (CaO) on the mesopores surfaces of the SBA-15 support after the first modification, and the successful subsequent 12-tungstophosphoric acid (HPW) functionalization. The superior stability of the synthesized catalysts (10wt%-HPW/CaSBA-15) was demonstrated (negligible change in both conversion - 75% and yield - 70%), without the need for catalyst regeneration. Such result was attributed to the strong interaction between HPW and SBA-15 via calcium bridging. Being alkaline in nature, calcium oxides in the inner pores readily reacted with highly acidic HPW introduced in the subsequent wetness incipient step, forming insoluble HPW acid sites on inner pore walls of SBA-15 via the calcium bridging. This modification deemed promising and other alkaline metals should be explored in the future.