Production of Hydroxypyruvic Acid by Glycerol Oxidation over Pt/CeO2-ZrO2-Bi2O3-PbO/SBA-16 Catalysts

Yeon-Bin Choi,Kunimitsu Morita,Nobuhito Imanaka,Naoyoshi Nunotani

doi:10.3390/catal12010069

Abstract

Pt/CeO2-ZrO2-Bi2O3-PbO/SBA-16 (SBA-16: Santa Barbara Amorphous No. 16) catalysts were synthesized to produce hydroxypyruvic acid by glycerol oxidation. In the catalysts, the introduction of PbO into CeO2-ZrO2-Bi2O3 improved the oxygen release and storage abilities owing to the synergistic redox reaction of Pb2+/4+ and Ce3+/4+, which facilitated the oxidation ability of Pt. In addition, the oxidation of the secondary OH group in glycerol might be accelerated by the geometric effects of glycerol, Pt, and Bi3+ or Pb2+/4+. Furthermore, the moderate reaction conditions such as room temperature and open-air atmosphere enabled the suppression of further oxidation of hydroxypyruvic acid. The highest catalytic activity was obtained for 7 wt% Pt/16 wt% Ce0.60Zr0.15Bi0.20Pb0.05O2−δ/SBA-16, which provided a hydroxypyruvic acid yield maximum of 24.6%, after the reaction for 6 h at 30 °C in atmospheric air.

Highlights

The oxidation of the secondary OH group in glycerol was facilitated in the presence of heavy metals in Group V (Bi) and IV (Pb), owing to the geometric effect [1], and Pt-Bi based catalysts have been investigated for the production of DHA [8,9]
In the glycerol oxidation process (Figure 1), further oxidation of glyceric acid (GA) or DHA results in the formation of glycolic acid (GLOA) and OA with high chemical stability via the intermediate compounds of hydroxypyruvic acid (HA), mesoxalic acid (MA), and tartronic acid (TA); the final product is carbon dioxide
To produce HA from glycerol, we introduced PbO into CeO2 -ZrO2 -Bi2 O3, In this study, to produce HA from glycerol, we introduced PbO into CeO 2-ZrO2because Pb showed selective oxidation of the secondary OH group similar to Bi [1]

Summary

Introduction

The terminal and secondary OH groups in glycerol are oxidized to form glyceraldehyde (GLA) and DHA, respectively, where GLA is oxidized into a more chemically stable compound of GA. The oxidation of the secondary OH group in glycerol was facilitated in the presence of heavy metals in Group V (Bi) and IV (Pb), owing to the geometric effect [1], and Pt-Bi based catalysts have been investigated for the production of DHA [8,9]. In the glycerol oxidation process (Figure 1), further oxidation of GA or DHA results in the formation of glycolic acid (GLOA) and OA with high chemical stability via the intermediate compounds of HA, mesoxalic acid (MA), and tartronic acid (TA); the final product is carbon dioxide. When the reactant is GA, in which one terminal OH group in glycerol has been oxidized, HA is reported to of Hydroxypyruvic Acid by Glycerol

Methods

Results

Conclusion