Cuy/MMgOx interfacial catalyst for selective alkyne hydrogenation and its preparation method

A method for preparing Cuy/MMgOx interfacial catalyst for selective alkyne hydrogenation comprising the following steps:

• A. Prepare the mixed salt solution by dissolving Cu salt, Mg salt and M salt in 100 ml deionized water according to the metal ion molar ratio of 1˜8/1˜4/1, the total amount of three metal ions is 1.0˜1.6 mol·L−1;
• two kinds of alkali solutions are dissolved in deionized water to prepare alkali solution with concentration of 1.0˜1.6 mol·L−1;
• Cu salt comprises Cu(NO3)2.3H2O or CuCl2;
• Mg salt comprises Mg(NO3)2.6H2O or MgCl2;
• M salt is any one of Fe(NO3)3.9H2O, FeCl3, Cr(NO3)3.9H2O, CrCl3, VCl3;
• alkali solutions are any two of NaOH, KOH, Na2CO3 or NaHCO3;
• B. Turn on the nucleation reactor, set the stator-rotor gap of the reactor to be 0.1˜0.5 mm and the rotation speed to be 100˜3000 rpm, and transport the mixed salt solution and alkali solution in step A to the reactor at a rate of 0.5˜2 mL·min−1 by a peristaltic pump for nucleation, and control the total number of metal cations in the salt solution to be equal to the number of anions in the alkali solution;
• collect nucleation slurry at slurry outlet;
• C. The nucleation slurry is transferred to a reaction kettle and crystallized at 60˜180° C. for 18˜36 h;
• after naturally cooling down to ambient temperature, the crystallized products are centrifuged and washed to neutral with deionized water, and then dried at 50˜80° C. for 24˜36 h, obtaining the layered double hydroxides (LDHs), namely CuyMMg4-LDHs precursor, where y is any integer between 1 and 8;
• D. The CuyMMg4-LDHs precursor obtained in step C is heated to 240˜300° C. at a heating rate of 5˜10° C.·min1 and calcined for 2˜6 h, obtaining the corresponding mixed metal oxide of CuyMMg4-MMO, where y is any integer between 1 and 8;
• E. The CuyMMg4-MMO obtained in step D is reduced at 400˜800° C. at a heating rate of 5˜10° C.·min1 in an atmosphere of 10 vol. % H2/N2 for 4˜6 h;
• after naturally cooling down to ambient temperature, 3 vol. % O2/N2 is introduced to passivate for 0.5˜1 h, obtaining Cuy-MMgOx interfacial catalyst, where y is any integer between 1 and 8;
• x is any number between 1 and 2.5.