High performance catalytic distillation using CNTs-based holistic catalyst for production of high quality biodiesel

Sulfonic acid/sulfur trioxide (SO3H/SO3) functionalized two-dimensional MoS2 nanosheets for high-performance photocatalysis of organic pollutants

We report the enhanced photocatalytic activity of sulfonic acid/sulfur trioxide (SO3H/SO3) functionalized two-dimensional (2D)-MoS2 (SO3H/SO3-MoS2) nanosheets synthesized using a one-pot hydrothermal method.

Hydrothermal liquefaction of Ulva prolifera macroalgae and the influence of base catalysts on products

Hydrothermal liquefaction of Ulva prolifera macroalgae (UM), an aquatic biomass, was carried out in an autoclave reactor at different temperature (270, 290 and 310 °C) and reaction holding time (10, 20 and 30 min.). The catalytic reactions of UM were carried out in the presence of three basic catalysts (KOH, NaOH and Na₂CO₃) with the different catalyst amount. Maximum bio-oil yield for non-catalytic liquefaction was (12.0 wt%) at 290 with 10 min reaction time. In the catalytic reaction the maximum bio-oil yield (26.7 wt%) was observed with KOH (0.1 g) catalyst. The chemical components and functional groups present in the bio-oils are identified by GC-MS, FT-IR, ¹H-NMR, TGA and elemental analysis techniques. Majorly nitrogen containing compounds were found with catalytic reaction in bio-oils. The higher heating value (33.6 MJ kg^-1) as well as the higher carbon content (64.2%) was observed in the case of catalytic liquefaction bio-oil.

Advances in nano-catalysts based biodiesel production from non-food feedstocks

This paper aims to examine the influence of various catalysts on biodiesel production, especially from non-food feedstocks with an ambition to optimize the catalytic biodiesel production. Homogenous acid catalysts are mainly used in biodiesel production, but they cannot be recovered and demand costly fuel purification as being corrosive. Similarly, enzyme catalysts are expensive in industrial-scale production of biodiesel. However, heterogeneous catalysts simplify the easy separation of product and by-products from the catalyst along with catalyst reusability and reduction of waste. Solid acid and base catalysts offer more advantages due to their non-toxicity, high surface area, reusability, higher stability, and the simplicity of purification. Solid base catalysts yield better activity than solid acid catalysts, however, they cannot esterify large amounts of free fatty acids (FFAs) in non-food feedstocks. The solid acid catalysts have the added advantages of being more tolerant to high amounts of FFAs and being able to simultaneously esterify FFAs and transesterify triglycerides in cheap feedstocks like waste cooking oil. Recently, an array of inorganic, organic and polymeric solid acid and nanomaterial-based catalysts have been developed using cheap feedstocks. However, the issues of low reactivity, small pore sizes, low stabilities, long reaction times, and high reaction temperatures still need to be solved. The developments of producing efficient, cheap, durable, and stable solid acid and nanomaterial-based catalysts have been critically reviewed in this study. Furthermore, the challenges and future perspectives of production of biodiesel and its industry growth have also been discussed.

Cross-linker mediated formation of sulfur-functionalized V2O5/graphene aerogels and their enhanced pseudocapacitive performance

The development of efficient synthesis methods for the preparation of vanadium oxide (V₂O₅)-graphene holds great promise considering the excellent performance of the composite in electrochemical applications. Herein, we report the cross-linking of a V₂O₅-graphene hybrid via a vanadium-thiourea redox system, which allowed the assembly of graphene oxide functional groups with V₂O₅ through the reducing ability of thiourea (TU) under room conditions within an impressively short reaction time (20 min). The resulting 3D composite aerogel forms a highly porous architecture of sulfur-functionalized interconnected networks. Such sulfur-functionalized transition metal oxide-graphene-based aerogels are excellent candidates in energy storage applications. When the vanadium oxide-graphene aerogel was evaluated as an electrode for a supercapacitor, a specific capacitance as high as 484.0 F g^-1 at 0.6 A g^-1 was obtained in a two-electrode cell configuration. This performance is much higher than that of the vanadium oxide-graphene aerogels prepared in the absence of thiourea. The vanadium oxide-graphene aerogel is able to deliver a remarkable energy density of 43.0 Wh kg^-1 at a power density of 0.48 kW kg^-1 at 0.6 A g^-1 and can hold 24.2 Wh kg^-1 at a maximum power density of 9.3 kW kg^-1 at 10 A g^-1. The symmetric supercapacitor assembled from the aerogel can retain 80% of its initial capacitance after 10 000 cycles.

The effect of the nanosize on surface properties of NiO nanoparticles for the adsorption of Quinolin-65

Using Quinolin-65 (Q-65) as a model-adsorbing compound for polar heavy hydrocarbons, the nanosize effect of NiO nanoparticles on the adsorption of Q-65 was investigated.