Continuous Flow Photocatalytic Degradation of Phenol Using Palladium@Mesoporous TiO2 Core@Shell Nanoparticles

Abstract

Palladium@mesoporous titania core@shell nanoparticles with uniform and narrow particle size distribution were synthesised using a four component ‘‘water in oil’’ microemulsion system. The prepared materials were well characterised using N2 adsorption–desorption measurements, temperature program oxidation, X-ray diffraction, ICP-OES, DRS UV-Vis, PL, TGA and transmission electron microscopy techniques. The core@shell nanoparticles showed very good absorption in both the UV and visible regions and a low bandgap, indicating that the prepared materials are visible-light-active, unlike the pristine TiO2 P25. The activity of the prepared materials was evaluated in the photodegradation of phenol using both UV and visible light, in batch and continuous flow trickle-bed and Taylor flow photoreactors. The prepared 2%Pd@mTiO2 core@shell nanoparticles showed better photocatalytic performance for phenol degradation in visible light in comparison to pristine TiO2 P25 and conventional 0.5%Pd/TiO2 P25 catalysts. The TiO2 P25 and conventional 0.5%Pd/TiO2 P25 catalysts showed gradual catalyst deactivation due to photocorrosion, the deposition of intermediates and Pd metal leaching. In comparison, the 2%Pd@mTiO2 catalyst showed higher catalyst stability and reusability. The 2%Pd@mTiO2 catalysts showed very high and stable phenol degradation (97% conversion) in continuous flow over 52 h. The results showed the feasibility of utilising the developed continuous Taylor flow photoreactor for phenol degradation or as a wastewater treatment plant.

Nanostructured Solid/Liquid Acid Catalysts for Glycerol Esterification: The Key to Convert Liability into Assets

“…Thus, converting the liability from biodiesel industry into the asset, adhering to the principles of circular economic approach, while at the same time improving the process economics and profitability of the overall biorefinery concept. In continuation of our group's interest in biomass derived drop in fuels [14][15][16][17][18][19][20][21][22][23], and environmental catalysis [24][25][26][27][28][29][30][31][32][33][34][35][36], herein we have critically reviewed the upgrading glycerol to glycerol esters as the products.…”

Nanostructured Solid/Liquid Acid Catalysts for Glycerol Esterification: The Key to Convert Liability into Assets

“…Thus, this accomplishes the conversion of the liability from the biodiesel industry into assets while adhering to the principles of the circular economy approach and improving the process economics and profitability of the overall biorefinery concept. In continuation of our group's interest in a biomass-derived drop in fuels [15][16][17][18][19][20][21][22][23][24] and an environmental catalysis [25][26][27][28][29][30][31][32][33][34][35][36][37][38], herein, we have critically reviewed the upgrading of glycerol to glycerol esters as the products.…”