Metal-organic framework derived Pd/ZrO2@CN as a stable catalyst for the catalytic hydrogenation of 2,3,5-trimethylbenzoquinone

Metal-organic frameworks (MOFs) have recently been identified as versatile sacrificing templates to construct functional nanomaterials for heterogeneous catalysis. Herein, we report a thermal transformation strategy to directly fabricate metal Pd nanoclusters inlaid within a ZrO2@nitrogen-doped porous carbon (Pd/ZrO2@CN) composite using Pd@NH2-UiO-66(Zr) as a precursor that was pre-synthesized by a one-pot hydrothermal method. The developed Pd/ZrO2@CN as a robust catalyst delivered remarkable stability and activity to the catalytic hydrogenation of 2,3,5-trimethylbenzoquinone (TMBQ) to 2,3,5-trimethylhydroquinone (TMHQ), a key reaction involved in vitamin E production. The hydrogenation was carried out at 110 degrees C with 1.0 MPa H-2, and it resulted in 98% TMHQ yield as the sole product over five consecutive cycles, outperforming the analogue Pd/ZrO2@C without nitrogen doping templated from Pd@UiO-66(Zr). The excellent catalytic properties of Pd/ZrO2@CN likely originated from the highly stable ultrafine Pd nanoclusters inlaid within ZrO2@CN matrix on account of the strong interaction between N and Pd, as well as on the Lewis acidity of ZrO2, which was beneficial to the hydrogenation.