Hydrotalcite-based catalyst, preparation method thereof and application of hydrotalcite-based catalyst in efficient catalytic preparation of vanillin

The invention discloses a hydrotalcite-based catalyst, a preparation method of the hydrotalcite-based catalyst and application of the hydrotalcite-based catalyst in efficient catalytic preparation of vanillin, and belongs to the technical field of functional catalyst preparation and biomass engineering. The preparation method comprises the following steps: firstly, preparing a hydrotalcite precursor containing metal cations Cu < 2 + >, Mg < 2 + > and Fe < 3 + > by using a coprecipitation method, and then roasting in air at 200-800 DEG C to obtain the composite metal oxide catalyst consisting of the three metal ions. The catalyst can efficiently catalyze lignin in a biomass material (such as cedarwood powder) to be depolymerized to generate vanillin, and the final vanillin yield is 20.61 wt% (calculated on the basis of the content of lignin in the cedarwood powder). The reaction system can directly take wood powder as a raw material, the reaction condition is mild, the catalyst is cheap and easy to prepare, an