Microwave-assisted hydrothermal synthesis of sulfonated TiO2-GO core–shell solid spheres as heterogeneous esterification mesoporous catalyst for biodiesel production
Publication Name
Energy Conversion and Management
Abstract
In accordance with the need for green production, the aim of current research is to synthesize a highly recyclable mesoporous SO H-GO@TiO catalyst possessing both Brönsted and Lewis acid sites for one-pot catalyzing the esterification of inexpensive acidic feedstocks namely palm fatty acid distillate (PFAD), containing free fatty acids (FFAs, >85 wt%) and a considerable amount of water (3 wt%). The mesoporous sulfonated GO@TiO catalyst was synthesized using a two-step hydrothermal microwave-assisted method featured by uniform dispersion of TiO nanoparticles inside the mesopore framework of GO and post-sulfonation treatment. The effect of different GO:Ti ratios (1:0.1, 1:0.3, 1:0.5, and 1:1) on textural properties were examined and therefore, the ratio of 1:1 was selected as the optimum ratio for further experiments. The mesoporous SO H-GO@TiO catalyst was characterized using Raman spectroscopy, Brunauer–Emmett–Teller (BET), X-Ray diffraction (XRD), temperature-programmed desorption (TPD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray (EDX), and the results revealed that the as-developed catalyst possessed desirable textural properties as well as strong acidity with a combination of both Brönsted and Lewis acid sites. Furthermore, the crystalline structure of the as-prepared mesoporous GO@TiO material remains unaltered after the post-sulfonation treatment. In addition, the synthesized mesoporous SO H-GO@TiO catalyst showed high stability for ten consecutive esterification reactions without additional treatments. 3 2 2 2 3 2 2 3 2
Open Access Status
This publication is not available as open access
Volume
238
Article Number
114165
Funding Number
03-01-20-2250FR
Funding Sponsor
Ministry of Higher Education, Malaysia