Glicerīna katalītiskā oksidēšana ar molekulāro skābekli heterogēnu katalizatoru klātbūtnē šķidrajā fāzē

Izpētīta glicerīna katalītiskā oksidēšana ar molekulāro skābekli dažādu heterogēnu katalizatoru klātbūtnē sārmainos ūdens šķīdumos. Noteikts, ka 3% Pd/Al2O3 ir aktīvs glicerīna oksidēšanas procesa katalizators. Oksidēšanas optimizēšanai veiktas vairākas eksperimentu sērijas, kurās mainīja temperatūru robežās 323-343 K, glicerīna koncentrāciju robežās 0,3-0,5 M; katalizatora koncentrāciju: n(glicerīna)/n(Pd) no 300 līdz 600; nātrija hidroksīda koncentrāciju no 0,7 līdz 1,5 M. Skābekļa parciālais spiediens bija nemainīgs un vienāds ar kopējo spiedienu = Pkop. = 1atm. Tika noteikts, ka temperatūras paaugstināšana, glicerīna un katalizatora koncentrācijas palielināšana paātrina oksidēšanas procesu. Nātrija hidroksīda koncentrācija maz ietekmē oksidēšanas ātrumu, bet ievērojami maina reakcijas mehānismu un selektivitāti. Tika noteikti glicerīnskābes un tartronskābes iegūšanas optimālie parametr

Oxidation of Glycerol with Oxygen in Alkaline Aqueous Solutions in the Presence of Supported Palladium Catalysts Prepared by the Extractive-Pyrolytic Method

Supported palladium catalysts for the selective oxidation of glycerol have been prepared by the extractive-pyrolytic method. For the preparation of catalysts, Al2O3, Y2O3, C, Pyrex were used as carriers. The main glycerol oxidation product in the presence of the obtained catalysts was glyceric acid. The by-products were tartronic, lactic, glycolic and oxalic acids. After optimizing the glycerol oxidation process, selective glyceric acid production conditions were found for the two most active new catalysts 1.25 % Pd/Al2O3 and 2.5 % Pd/Al2O3

Oxidation of Glycerol with Oxygen in Alkaline Aqueous Solutions in the Presence of Supported Palladium Catalysts Prepared by the Extractive-Pyrolytic Method

Supported palladium catalysts for the selective oxidation of glycerol have been prepared by the extractive-pyrolytic method. For the preparation of catalysts, Al2O3, Y2O3, C, Pyrex were used as carriers. The main glycerol oxidation product in the presence of the obtained catalysts was glyceric acid. The by-products were tartronic, lactic, glycolic and oxalic acids. After optimizing the glycerol oxidation process, selective glyceric acid production conditions were found for the two most active new catalysts 1.25 % Pd/Al2O3 and 2.5 % Pd/Al2O3.

Selective Liquid Phase Oxidation of Glycerol to Glyceric Acid over Novel Supported Pt Catalysts

Several supported platinum catalysts were prepared by the extractive–pyrolytic method for the selective production of glyceric acid from glycerol. Al2O3, Y2O3, Lu2O3, ZrO2–Y2O3 TiO2, SG, Fe2O3, γ-AlO(OH) and C were used as the catalyst supports. Glycerol oxidation was performed in alkaline solutions and oxygen was used as the oxidant. The optimal catalyst preparation parameters and glycerol oxidation conditions to obtain glyceric acid were determined. The best result (57 % selectivity to glyceric acid with 92 % glycerol conversion) was achieved on a 4.8 % Pt/Al2O3 catalyst