Lanthanum phosphate:an efficient catalyst for acrylic acid production through lactic acid dehydration

Abstract In this work, biomass-based platform molecule lactic acid conversion to acrylic acid has been studied. A series of lanthanum phosphate (LaP) catalysts prepared by varying the lanthanum to phosphorus (La/P) mole ratio (i.e., 0.2, 0.35, 0.5, 1.0, and 2.0) and also prepared at different calcination temperatures (i.e., 400, 500, 600, and 800 °C) were investigated. The catalysts were characterized by using different techniques and tested in the dehydration of lactic acid (LA) to acrylic acid (AA) production. All the synthesized catalysts were characterized to analyze the physicochemical properties such as degree of crystallinity, total surface acidity, specific surface area, and morphology. The La/P mole ratio was found to be significant in designing the optimized catalytic system. The NH₃-TPD results imply that all the catalysts exhibited varied amount of total acidity with phosphate loadings, which are mostly weak acid sites. The weak acid sites which are mainly Lewis acidity type played an important role in producing AA selectively and efficiently from the LA conversion. The most optimized reaction conditions were determined to obtain the highest LA conversion, selectivity, and AA yield. The catalyst with an La/P mole ratio of 0.35 and calcined at 500 °C exhibited the best performance with complete LA conversion, AA selectivity of ~ 74%, and a maximum yield of AA of ~ 74%. Furthermore, the LaP(0.35)[500] catalyst was successfully tested at three different time on streams and found to be stable

Selective hydrogenolysis of biodiesel waste bioglycerol over titanium phosphate (TiP) catalysts:the effect of Pt & WO₃ loadings

Abstract Glycerol is an important by-product (biowaste) from biodiesel production. Transformation of glycerol into value-added compounds is critical in improving the overall efficiency of the biodiesel production. In this work, a sustainable and cleaner production of 1,3-propanediol (1,3-PDO) by vapor phase hydrogenolysis of glycerol was performed over titanium phosphate (TiP) supported catalysts by varying the Pt and WO₃ loadings (5–20 wt.%). The WO₃ promoted Pt modified TiP catalysts were prepared by a simple wet impregnation method and characterized by various analytical techniques in determining the key properties. Furthermore, the catalyst activity and stability were studied under different reaction conditions. The synergistic effects of Pt and WO₃ loadings on the final performance of the catalyst has been significant in improving the hydrogen transfer rate. Both Pt and WO₃ promotional effects is envisaged the enhanced catalytic properties in conjunction with TiP support acidity. WO₃ incorporation increased Brønsted acidity and formed strong interactions with Pt over TiP support. Both Lewis and Brønsted acid sites presented but BAS played a key role in enhancing the 1,3-PDO selectivity in a bifunctional dehydration-hydrogenation reaction mechanism of glycerol. The effect of reaction temperature, contact times and the weight hour space velocity were evaluated. Overall, under optimized reaction conditions, 2 wt.% Pt-10 wt.% WO₃/TiP catalyst displayed superior activity with a maximum glycerol conversion of ~ 85% and ~ 51% of 1,3-PDO selectivity achieved at time on stream of 4 h