One-Step Synthesis of Cu–ZnO@C from a 1D Complex [Cu0.02Zn0.98(C8H3NO6)(C12H8N2)]n for Catalytic Hydroxylation of Benzene to Phenol

A novel one-dimensional bimetallic complex [Cu0.02Zn0.98(C8H3NO6)(C12H8N2)]n (“Complex”) has been synthesized by a hydrothermal method. A Cu–ZnO@C composite was obtained by a one-step pyrolysis of Complex. Correlated with the characterization results, it is confirmed that both metallic Cu0 and ZnO nanoparticles were highly dispersed on/in the carbon substrate. This simple one-step pyrolysis method avoids the high-temperature pretreatment under H2 commonly required for preparation of such Cu–ZnO catalysts. The Cu–ZnO@C composite was tested with respect to its catalytic activities for the hydroxylation of benzene to phenol with H2O2. The results indicate that the benzene conversion, phenol yield, and phenol selectivity reached the maximum values (55.7%, 32%, and 57.5%, respectively) at Complex carbonized at 600 °C, and were higher than those of the commercial mixed sample. Compared with the other candidate catalysts, the turnover frequency (TOF) of our Cu–ZnO@C catalyst (117.9 mmol mol−1 s−1) can be ranked at the top. The higher catalytic activities should be due to the highly dispersed metallic Cu0 and ZnO particles as well as their synergistic interaction.