Glycerol is now excessively produced from oleochemical and biodiesel industry and efforts to convert it to value-added substances are worthwhile. The catalytic etherification of glycerol using mixed alcium–lanthanum oxide supported on MCM-41 as a stable heterogeneous basic catalyst was investigated in this study. The heterogeneous mesoporous basic catalysts were synthesized by wet impregnation of MCM-41 with calcium nitrate and lanthanum nitrate as precursors. The surface and structural properties of the prepared catalysts were when characterized using SEM, EDX, XRD and FTIR methods. MCM-41 and modified MCM-41 were then used in the solventless etherification of glycerol to produce diglycerol as the desired product. The reaction was performed at 250 °C for 8 h, and catalyst activity was evaluated and correlated with the properties of the catalysts. The conversion of glycerol managed to reach 91.3%, and the corresponding diglycerol yield was 42.6%. The distribution of diglycerol isomer in the etherification of glycerol was elucidated, and the value of the sum of two dimers (ββ’ + αβ = 67%) was found to be higher than that of αα’ dimer (33%) after 8 h of reaction. Thus, the major reaction was deemed to have occurred inside the internal mesoporous pores instead of on the external surface area when 20% CaLa/MCM-41 was used to catalyze the reaction.

Professor Dr Ahmad Zuhairi Abdullah is currently the Deputy Dean (Research, Postgraduate & Network) at School of Chemical Engineering, Universiti Sains Malaysia. He received his B. Tech (Hons) in 1995 from Universiti Sains Malaysia and subsequently MSc (2000) and PhD (2004) in the field of chemical process technology and chemical engineering, respectively. He has been a registered chemist with Malaysian Institute of Chemistry since 2005. His research works mostly encompass catalysis and chemical reactions involved in the production of renewable energy sources, downstream oleochemicals, waste treatment and green technology which are definitely relevant and strategic to Malaysian economy. Some of them involve collaboration with industries such as Felda, WD-Media, Pacific West Foods and SilTerra to solve their problems and to improve efficiency in order to remain competitive in the future. He is among the pioneering researchers in the world to focus on the use of ultrasound to accelerate heterogeneous catalytic processes. He is the recipient of several innovation and publication awards based on his research works. Many industry engineers and research scientists with higher qualification in these areas have been successfully trained. His research expertise is often sought after for the assessment of Environmental Impact Assessment (EIA) reports on proposed strategic commercial projects such as oil refinery, petrochemical complex, sanitary landfill, smelting plant, used acid lead battery, paper mill etc. Various industrial problems have been successfully solved through his consultancy projects. He has been involved in the propagation of science and technology through nearly 200 refereed publications in journals and book chapters mainly as the main author, and also involves as a technical committee member to nearly 80 international scientific conferences held across the globe. Many invitations on various roles have also been received to share his research experience with government officers, research scientists, junior researchers and school children. The objectives of the events vary from the critical research skills, understanding science, promotion of sustainability, community awareness, carrier development to the understanding of policy and regulatory aspects. Few travel grants have been received to share his research experience in Japan, Indonesia and Laos. Research collaborations with local and international counterparts have been successfully established for the advancement of science. He also acts as an examiner to many postgraduate theses locally and internationally as well as an article reviewer to more than 80 different leading international journals in his area of expertise. In addition, he is an evaluator to research proposals received from the university, local ministries as well as international scientific associations such as American Chemical Society and the Qatar National Research Foundation. He is one of the recipients of the Top Research Scientist Malaysia 2014 award. His h-index (Scopus) is currently stands at 34.