473-81-4Relevant academic research and scientific papers
The selective oxidation of glycerol over metal-free photocatalysts: insights into the solvent effect on catalytic efficiency and product distribution
Fan, Mingming,Haryonob, Agus,Jiang, Pingping,Leng, Yan,Yue, Chengguang,Zhang, Pingbo
, p. 3385 - 3392 (2021/06/06)
Selective oxidation of glycerol to high value-added derivatives is a promising biomass conversion pathway, but the related reaction mechanism, in particular the solvent effect, is rarely studied. In this work, O-doped g-C3N4was used as a metal-free catalyst to catalyze the selective oxidation of glycerol in different solvents. It was found that solvents can affect both catalytic efficiency and product distribution. A series of controlled experiments and theoretical calculation were applied to attest that the difference in interaction between glycerol and catalysts in different solvents is the main factor: competitive adsorption and hydrogen bond network from water inhibit the adsorption and activation of glycerol on the catalyst surface and reduce the conversion efficiency, while in acetonitrile, the stronger adsorption makes the oxidation reaction continue to yield esters. Two reaction routes in different solvents over O-doped g-C3N4are proposed for the first time, which is helpful for people to better understand the related reaction mechanism.
PROCESSES FOR PREPARING ALDARIC, ALDONIC, AND URONIC ACIDS
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Paragraph 0110-0111, (2021/05/29)
Various processes for preparing aldaric acids, aldonic acids, uronic acids, and/or lactone(s) thereof are described. For example, processes for preparing a C2-C7 aldaric acid and/or lactone(s) thereof by the catalytic oxidation of a C2-C7 aldonic acid and/or lactone(s) thereof and/or a C2-C7 aldose are described.
A proof of concept for cooperation from the quinone groups adjacent to N sites during the metal-free oxidation of glycerol by nitrogen-rich graphene oxide
Barlocco, Ilaria,Dogra, Ashima,Gupta, Neeraj,Sharma, Vinit,Villa, Alberto
supporting information, p. 19651 - 19654 (2021/11/12)
Glycerol is a key by-product in biodiesel production and can be utilized in the synthesis of value-added chemicals. The low cost and fairly abundant availability of glycerol can be advantageous in producing a variety of pharmaceuticals and cosmetic products. Among the various catalytic transformations, selective oxidation is a promising pathway for the valorization of glycerol. In this present report, we deliver a first proof of concept for the involvement of quinone groups adjacent to N sites on the GO surface, for the selective oxidation of glycerol to dihydroxyacetone (DHA). Graphene oxide is covalently functionalized with 2,4-dihydroxypyridine (DHP), which resembles the identified active sites in the carbon clusters. As anticipated, the DHP-functionalized graphene oxide catalyst (DHP@GO) improved the conversion of glycerol to DHA, the main product, along with minor amounts of glyceric acid (GA) and fumaric acid (FA).
Assembly of platinum nanoparticles and single-atom bismuth for selective oxidation of glycerol
Huang, Ning,Jiang, Dong,Jiang, Pingping,Leng, Yan,Lu, Yubing,Tian, Jinshu,Yue, Chenguang,Zhang, Pingbo,Zhang, Zihao
supporting information, p. 25576 - 25584 (2021/12/07)
Selective oxidation of the secondary hydroxyl group of glycerol to dihydroxyacetone (DHA) is an extremely challenging yet important reaction. The main difficulty is that the three hydroxyl groups in glycerol are prone to randomly oxidize, resulting in an unsatisfactory DHA selectivity. We show here that an assembly of platinum nanoparticles (NPs, ～2 nm) and N-stabilized single-atom bismuth (Bi), namely Pt/Bi@NC, shows a record-high DHA selectivity of ～95.0% towards glycerol oxidation under optimized reaction conditions. Characterization and theoretical calculations confirm that single-atom Bi in the vicinity of Pt NPs provides a preferred site to chelate with the primary -OH of glycerol, and its secondary -OH is prone to bind to a surface Pt atom of a Pt NP with a shorter Pt-H bond length. This as-formed unique adsorption configuration of glycerol on the Pt-Bi dual site significantly facilitates the oxidation of the secondary -OH of glycerol, thus contributing to a record-high selectivity to DHA. This journal is
Transfer hydrogenation of CO2into formaldehyde from aqueous glycerol heterogeneously catalyzed by Ru bound to LDH
Deng, Lidan,Liu, Xiaowei,Xu, Jie,Zhou, Zijian,Feng, Shixiang,Wang, Zheng,Xu, Minghou
supporting information, p. 5167 - 5170 (2021/05/31)
Aqueous glycerol was used in this study as a liquid-phase hydrogen source for the hydrogenation of CO2. It was found that hydrogen could be efficiently evolved from aqueous glycerol upon highly dispersed Ru on layered double hydroxide (LDH), inducing the transformation of CO2 into formaldehyde under base-free conditions at low temperature.
Selective oxidation of glycerol over different shaped WO3 supported Pt NPs
Yang, Lihua,Jiang, Yuanyuan,Zhu, Zihui,Hou, Zhaoyin
, (2021/04/19)
In this work, different shaped WO3 (rod-like, lamellar and cuboid) supported Pt catalysts were prepared in a facile routine and tested in the selective oxidation of glycerol in base-free aqueous solution. Characterizations indicated that rod-like WO3 supported Pt catalyst (Pt/R-WO3) possesses higher surface area because of the formation of vertical pore channels and highly exposed plane (100), the deposited Pt atoms combined strongly with the terminal [sbnd]W[dbnd]O in rod-like WO3. These properties promoted the adsorption, storage and surface diffusion of oxygen over Pt/R-WO3 which exhibited the excellent activity for the selective oxidation of glycerol. And the higher amount of acid sites on the surface of Pt/R-WO3 enhanced the selectivity of glyceric acid. The calculated turnover frequency of each Pt atom in Pt/R-WO3 reached 946 h–1 at 60 °C.
Influence of Pd and Au on electrochemical valorization of glycerol over Ni-rich surfaces
Houache, Mohamed S.E.,Shubair, Asma,Sandoval, Mario G.,Safari, Reza,Botton, Gianluigi A.,Jasen, Paula V.,González, Estela A.,Baranova, Elena A.
, p. 1 - 13 (2021/03/03)
Herein we synthesized bi-metallic Pd@Ni and Au@Ni core-shell-like nanoparticles (NPs) for glycerol electrooxidation reaction (GEOR) in alkaline media. The morphological, structural and surface properties of the NPs were evaluated using a range of physicochemical techniques. The catalytic activity and stability were studied using the three-electrode electrochemical cell and 25 cm2- continuous electrolysis cell. Among different atomic ratios, Ni80Pd20 and Ni90Au10 nanoparticles showed the highest current densities which are ~4.5 and 4.2 times higher than spherical Ni, respectively. The addition of Pd and Au (a remarkable glycerate selectivity of ~73.1% and 65.7% for Ni80Pd20 and Ni90Au10 catalysts at 1.3 V and 50 °C, respectively. Notably, after 6 h of electrolysis Pd@Ni and Au@Ni tend to suppress the C-C bond cleavage, compared to Ni at any applied potentials and temperatures. The DFT calculations predicted that the addition of Pd or Au to Ni reduces the work function of M@Ni NPs, which strengthens the OH adsorption and enhances the removal of GEOR intermediates.
Hydrogen and chemicals from alcohols through electrochemical reforming by Pd-CeO2/C electrocatalyst
Bellini, Marco,Pagliaro, Maria V.,Marchionni, Andrea,Filippi, Jonathan,Miller, Hamish A.,Bevilacqua, Manuela,Lavacchi, Alessandro,Oberhauser, Werner,Mahmoudian, Jafar,Innocenti, Massimo,Fornasiero, Paolo,Vizza, Francesco
, (2021/01/25)
The development of low-cost and sustainable hydrogen production is of primary importance for a future transition to sustainable energy. In this work, the selective and simultaneous production of pure hydrogen and chemicals from renewable alcohols is achieved using an anion exchange membrane electrolysis cell (electrochemical reforming) employing a nanostructured Pd-CeO2/C anode. The catalyst exhibits high activity for alcohol electrooxidation (e.g. 474 mA cm?2 with EtOH at 60 °C) and the electrolysis cell produces high volumes of hydrogen (1.73 l min?1 m?2) at low electrical energy input (Ecost = 6 kWh kgH2?1 with formate as substrate). A complete analysis of the alcohol oxidation products from several alcohols (methanol, ethanol, 1,2-propandiol, ethylene glycol, glycerol and 1,4-butanediol) shows high selectivity in the formation of valuable chemicals such as acetate from ethanol (100%) and lactate from 1,2-propandiol (84%). Importantly for industrial application, in batch experiments the Pd-CeO2/C catalyst achieves conversion efficiencies above 80% for both formate and methanol, and 95% for ethanol.
Ambient base-free glycerol oxidation over bimetallic PdFe/SiO2 by in situ generated active oxygen species
Underhill, Ricci,Douthwaite, Mark,Lewis, Richard J.,Miedziak, Peter J.,Armstrong, Robert D.,Morgan, David J.,Freakley, Simon J.,Davies, Thomas,Folli, Andrea,Murphy, Damien M.,He, Qian,Akdim, Ouardia,Edwards, Jennifer K.,Hutchings, Graham J.
, p. 303 - 324 (2021/01/07)
Low temperature oxidation of alcohols over heterogeneous catalysts is exceptionally challenging, particularly under neutral conditions. Herein, we report on an efficient, base-free method to oxidise glycerol over a 0.5%Pd-0.5%Fe/SiO2 catalyst at ambient temperature in the presence of gaseous H2 and O2. The exceptional catalytic performance was attributed to the in situ formation of highly reactive surface-bound oxygenated species, which promote the dehydrogenation on the alcohol. The PdFe bimetallic catalyst was determined to be significantly more active than corresponding monometallic analogues, highlighting the important role both metals have in this oxidative transformation. Fe leaching was confirmed to occur over the course of the reaction but sequestering experiments, involving the addition of bare carbon to the reactions, confirmed that the reaction was predominantly heterogeneous in nature. Investigations with electron paramagnetic resonance spectroscopy suggested that the reactivity in the early stages was mediated by surface-bound reactive oxygen species; no homogeneous radical species were observed in solution. This theory was further evidenced by a direct H2O2 synthesis study, which confirmed that the presence of Fe in the bimetallic catalyst neither improved the synthesis of H2O2 nor promoted its decomposition over the PdFe/SiO2 catalyst.
Electro-oxidation of glycerol into formic acid by nickel-copper electrocatalysts
Shen, Yi,Zhang, Jiali
, (2021/09/11)
Herein, non-precious metallic nickel-copper electrocatalysts were synthesized for electro-oxidation of glycerol in alkaline electrolytes. Activated carbon felt (ACF) is used as a supporting material because of its good conductivity, chemical inertness, and porous structure which is conducive to the transport of the reactants/electrons. The structural features of the catalysts were characterized by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The electrochemical activity of the catalysts was revealed by cyclic voltammetry, linear sweeping voltammetry, and chronoamperometry. The electrochemical results show that the Cu1Ni1@ACF catalyst possesses the highest current density of 1.31 mA cm-2 at 1.895 V. High-performance liquid chromatography results show that the as-prepared catalysts have high selectivities for formic acid (FA). Especially, the Cu1Ni1@ACF catalyst yields a selectivity of 97.4% for FA, which has so far been the largest value reported in the literature. Additionally, the effects of applied potentials and reaction time on product selectivity were studied.
