Core-shell structure supported tungsten composite catalyst and preparation method and use thereof

A preparation method of a core-shell structure supported tungsten composite catalyst, comprising the steps of:

• step 1), adding a reducing agent and a base into an aqueous solution of iron compound, heating to 50-80° C. and stirring to obtain Fe3O4 colloid;
• step 2), adding the Fe3O4 colloid obtained in the step 1), tetraethyl orthosilicate and a hydrolysis catalyst into an appropriate amount of dispersion solvent and allowing to react for 4-8 hours to obtain SiO2/Fe3O4 composite nano-particles;
• and
• step 3), adding the SiO2/Fe3O4 composite nano-particles obtained in step 2) into an aqueous solution of ammonium metatungstate, stirring for 8-14 hours and drying at 90-150° C. to obtain a first solid, which is calcined at 450-650° C. for 1-6 hours to obtain a magnetic separable core-shell structure supported tungsten composite catalyst, WO3/SiO2/Fe3O4;
• wherein the molar ratio of the iron compound:
• tetraethyl orthosilicate:ammonium metatungstate=1:1-10:0.1-1;
• and wherein the iron compound is FeCl3, FeCl3.6H2O or ferric triacetylacetonate;
• the reducing agent is Na2SO3, ascorbic acid or hydrazine hydrate;
• and the base is aqueous ammonia, sodium hydroxide or sodium acetate.