Selective oxidation of veratryl alcohol to veratraldehyde using more active catalyst in a continuous reactor

Abstract

Verataldehyde (3,4-dimethoxybenzaldehyde) was used as a precursor for various industrial applications, such as flavouring agents, odorants, and pharmaceuticals. The major approach of this study is to convert veratryl alcohol to veratraldehyde, and the whole reaction was carried out in a continuous-process reactor. A bimetallic catalyst was prepared by the wet impregnation method in four different ratios by varying the metal percentage (Mn-10 % and Zn-5–20 %). These metals were incorporated into the activated carbon, which has a high mesoporous nature and was prepared from the used waste surgical mask. The catalysts were subjected to analysis and characterization. Textural characteristics, morphology, chemical properties, and stability of the catalyst were ascertained by utilizing X-ray diffraction, Brunauer-Emmett-Teller, N2 adsorption–desorption isotherm, Fourier transform infrared spectroscopy, and a transmission electron microscope. By varying the continuous reactor parameters such as pressure, temperature, WHSV−1, and reaction time, the catalysts were optimised to achieve the maximum conversion and selectivity of the veratryl alcohol. The AC-Mn (10 %)/Zn (15 %) catalyst was carried out under ideal conditions: 90 °C, 5 mL of TBHP as the solvent, 15 bar of pressure, and 3.2 g of catalyst proven a greater result in the reaction with a conversion and selectivity of 98 %. The stability and reusability of the catalyst were confirmed by delivering a 95.8 % yield even after five reaction runs. A continuous reaction study can provide valuable inputs for the commercial exploitation of veratryl alcohol (VA) to veratraldehyde (VAld). Again, catalytic support was synthesised utilising waste products, and the metal components are cost-effective as compared to noble metals.

Keywords

• Waste face mask
• Activated carbon
• Manganese
• Zinc
• Veratryl alcohol
• Veratryl aldehyde