A readily available and efficient Pt/P25 (TiO₂) catalyst for glycerol selective oxidation

Abstract

In this work, a commercial P25 (TiO 2 ) with phase junctions between ( 101) and ( 110) faces supported Pt catalyst was prepared for glycerol selective oxidation, giving a decent 76.8% glyceric acid (GLYA) yield, and good stability. The kinetic experiments calculated apparent activation energy, turnover frequency (TOF), and reaction rates, demonstrating Pt/P25 could facilitate glyceraldehyde (GLYAD) formation and inhibit GLYA over-oxidation. Series of structural techniques confirmed the 101/110 junctions in P25 contributed electronic effect on Pt through metal-support interface, which improved the oxygen activation ability and optimized the GLYAD/GLYA adsorption modes. Furthermore, progressive scale-up reactions were tested and the mass transfer limitations under different conditions were thoroughly studied. The obtained mass transfer factors suggested the gas-liquid and liquid-solid mass transfer were severely limited. Finally, through optimizing the conditions, Pt/P25 catalyst achieved 75.8% GLYA yield at 300 ml-scale reaction, realizing equivalent magnification with the 5 ml-scale experiment.

Role of Support in the Selective, Aerobic Methane Oxidation to Formaldehyde over Pt/TiO2

“…In the absence of water, the rate of methane conversion over Pt/TiO 2 –P25 is higher than that over Pt/TiO 2 –Rutile despite having similar metal loadings and similar metal dispersion. A similar result was obtained by Rui et al, which may be rationalized by a higher electron density on platinum in the presence of P25 . This would then enhance oxygen activation over platinum and improve the oxidation activity .…”

“…A similar result was obtained by Rui et al, 38 which may be rationalized by a higher electron density on platinum in the presence of P25. 39 This would then enhance oxygen activation over platinum and improve the oxidation activity. 40 The turnover frequency for methane conversion over Pt/TiO 2 − Rutile in the presence of liquid water is almost twice the turnover frequency for methane conversion over Pt/TiO 2 −P25 (see Table 2).…”

Boosting primary amines renewable tandem synthesis via defect engineering of NiCo alloy

“…2,3 Therefore, developing novel synthetic approaches aiming at employing greener substrates and less-toxic ingredients, generating less waste, and working under milder conditions, is a major research endeavor. Biomass is a kind of renewable and carbon-neutral resource, [4][5][6][7] aldehydes are readily available from lignocellulosic biomass, 8,9 reductive amination of aldehydes is an environment-friendly and atom-economical way to prepare primary amine compounds. 10 Taking the reductive amination of biomass platform compound 5-hydroxymethylfurfural (5-HMF) to 5-aminomethyl-2-furanyl alcohol (AMF) as an example, it involves a complex reaction network as shown in Scheme 1.…”

“…Therefore, developing novel synthetic approaches aiming at employing greener substrates and less‐toxic ingredients, generating less waste, and working under milder conditions, is a major research endeavor. Biomass is a kind of renewable and carbon‐neutral resource, 4–7 aldehydes are readily available from lignocellulosic biomass, 8,9 reductive amination of aldehydes is an environment‐friendly and atom‐economical way to prepare primary amine compounds 10 …”

“…As listed in Table2, the chosen aldehydes were classified into biomass-derived aldehydes (entry 1, 2), aromatic aldehydes (entry 3), S C H E M E 2 Possible catalytic mechanism for 5-HMF reductive amination over NiCo catalysts. aliphatic aldehydes (entry 4, 5), and ketones(6). The results showed catalyst exhibited decent catalytic performance in the universality experiment.4 | CONCLUSIONIn this work, we developed a series of NiCo alloy catalysts (NiCo/ NiCoAlO x -2, NiCo/NiCoAlO x -5, and NiCo/NiCoAlO x -10) with different defects' concentration by changing the heating rate to adjust the driving force of crystallization.…”