Nanometric Pd-confined mesoporous silica as high-efficient catalyst for toluene low temperature removal: Effects of support morphology and textural property

Recent Advances in the Catalytic Oxidation of Volatile Organic Compounds: A Review Based on Pollutant Sorts and Sources

“…Porous silica materials, metal oxides and hydrotalcite-derived oxides are typically utilized as the supports for Pd active phase. 263,[483][484][485][486][487][488] We have previously reported on the use of porous silicas, including microporous zeolites, mesoporous molecular sieves, and micro-/mesoporous composites as supports for Pd nanoparticles. In our investigations, we determined that the ZSM-5 is a stable and coke-resistant support for Pd supported catalysts in this reaction and that the acidity of the support can influence the Pd dispersion, redox potential and CO2 desorption of the catalyst.…”

“…492 Other synthesis procedures have reported using a "two-solvent" approach, which combines the use of a hydrophobic solvent, such as hexane, with a hydrophilic solvent such as water. 483,484 We prepared a Pd/SBA-15 catalyst using this approach and determined that acid sites on the catalyst further assisted with the Pd dispersion. Furthermore, the Pd/SBA-15 catalyst exhibited a high thermal stability and a high tolerance to moisture.…”

“…demonstrated that supported Pd catalysts are often more stable than supported Pt catalysts for this reaction. Porous silica materials, metal oxides, and hydrotalcite-derived oxides are typically utilized as the supports for a Pd active phase. ,− We have previously reported on the use of porous silicas, including microporous zeolites, mesoporous molecular sieves, and micro-/mesoporous composites as supports for Pd nanoparticles. In our investigations, we determined that ZSM-5 is a stable and coke-resistant support for supported Pd catalysts in this reaction, and that the acidity of the support can influence the Pd dispersion, redox potential and CO 2 desorption of the catalyst. , Of the catalysts we tested, a Pd/ZSM-5 catalyst (Si-to-Al molar ratio of 25) showed the best activity for this reaction; a total toluene decomposition was observed at 220 °C (GHSV = 32 000 h –1 ) .…”

“…It was also determined that the solvent used in the preparation (ethanol, water, tetrahydrofuran, dimethyl sulfoxide, and N,N -dimethylformamide) had a significant effect on the resultant Pd dispersion; the highest Pd dispersion was observed when N,N -dimethylformamide was used . Other synthesis procedures have reported using a “two-solvent” approach, which combines the use of a hydrophobic solvent, such as hexane, with a hydrophilic solvent such as water. , We prepared a Pd/SBA-15 catalyst using this approach and determined that acid sites on catalyst further assisted with Pd dispersion. Furthermore, the Pd/SBA-15 catalyst possessed an excellent thermal stability and a high tolerance to moisture.…”

Fabrication of Pd3@Beta for catalytic combustion of VOCs by efficient Pd3 cluster and seed-directed hydrothermal syntheses

“…This phenomenon can be attributed to the following reasons: the dispersion of Pd, the proportion of Pd 0 and the structure properties of support. 19,[36][37][38][39][40][41] He et al reported that metallic Pd species (Pd 0 ) is active for hydrocarbons combustion and can catalyze VOCs directly into CO 2 and H 2 O, which benets the catalytic activity. 41,42 The high Pd dispersion would offer more catalytic active sites for toluene combustion and the mesoporous zeolite support can accelerate diffusion of reactants to active sites in Pd 3 @Beta, both of which can enhance toluene combustion rate.…”