Lanthanum-doped nickel-based composite metal oxide catalyst for hydrogenation of isophthalonitrile to produce meta-xylenediamine†

NiMAl (4 : 3 : 1)-LDO (M = Ca, Ba, and Mg) catalysts were prepared by co-precipitation. The optimal Ni₄Mg₃Al catalyst was selected and further modified with La to create the Ni₄Mg₃La_0.15Al composite metal oxide catalyst. Under optimised reaction conditions, the isophthalonitrile (IPN) conversion reached 100%, and the selectivity to the target product meta-xylenediamine (MXDA) was remarkably high at 98.68%, while the selectivity of the by-product was as low as 0.05%. After ten reaction cycles, no significant decrease in the IPN conversion or MXDA selectivity was observed. The catalyst also exhibited excellent stability in a fixed-bed reactor over 400 hours, with the IPN conversion remaining at above 99% and MXDA selectivity maintained at an average of around 90%. The characterization results of the catalyst revealed that La addition strengthened the interaction between active Ni and the support, increased the content of strong basic sites in the catalyst, reduced the Ni nanoparticle size, and improved dispersion, leading to improved catalytic activity and stability.