Catalytic Performance Of Transition Metal Phosphides For The Hydrogenation Of α,β-Unsaturated Aldehydes

With the development and utilization of biomass resources,more and moreα,β-unsaturated aldehydes using biomass as raw materials are used to prepare high value-added chemicals.In this paper,the hydrogenation of cinnamaldehyde was selected as the probe reaction to study the catalytic performance of transition metal phosphides as catalysts in the hydrogenation system ofα,β-unsaturated aldehydes.After the optimization and screening of metals,supports and synthesis methods,nickel phosphide catalysts were selected as the research focus.Catalysts with different nickel-to-phosphorus ratios were prepared by solvothermal method,and characterization studies were carried out.Stable Ni₂P and Ni P₂ nanoparticles were successfully prepared by controlling the amount of nickel source and phosphorus source added during the synthesis.Both catalysts showed efficient catalytic performance in the hydrogenation of cinnamaldehyde,and the conversion rate reached 100%after 150 minutes at 150°C.The catalyst has 100%selectivity to cinnamyl alcohol.The same catalytic effect can also be exhibited in reaction systems such as furfural hydrogenation.The excellent adsorption performance of the nickel phosphide catalyst for reactants and hydrogen was verified by H₂-TPD and cold state experiments.The high efficiency of adsorption also helps that the reaction rate is affected by the kinetics,and the kinetic fitting results were closer to the first-order reaction.Combined with the differences in the reaction results,the hydrogen source utilization and activation performance of the catalysts were experimentally studied,which confirmed the application of the catalytic hydrogen transfer mechanism in this experiment.The influence of external diffusion was eliminated by adjusting the rotational speed.The reaction rates at different reaction temperatures were tested,and the activation energy of the catalytic reaction of different catalysts was calculated.The difference in activation energy also confirmed the difference in reaction paths.Combined with the universal experiment,it is proved that catalysts with different nickel-to-phosphorus ratios can be used to achieve high conversion and high-selectivity preparation for different target products,and a series of experiments on the stability of the catalyst have been carried out.The nickel phosphide catalyst showed excellent performance.stability and high application potential.