The current established catalytic processes in chemical industries use metals, in many cases precious metals, or metal oxides as catalysts. These are often energy-consuming and not highly selective, wasting resources and producing greenhouse gases. In the past few years, metal-free materials, such as graphite oxide, graphene, carbon nanotubes, have attracted much attention in the catalytic field. Unlike those carbon materials, nanodiamond and related nanocarbon materials (URNM) including buckdiamond and onion-like carbon, as newly-developing catalysts possess the unique nature including smaller particle size, better thermostability and higher surface energy, as well as specific π and σ electronic structures, tunable surface groups and hence exhibit the competitive activities compared with the conventional metal catalysts toward some important catalytic reactions.

Prof. SU and co-workers achieve the promising activities and develop the heterogeneous catalysis using only URNM and modified URNM as catalysts and a variety of reactions are introduced in the present work. The detailed relationships between the surface chemical components and their properties, edge structure and catalytic performance are demonstrated. For example, a metal-free reaction pathway is described where onion-like carbon as a low-cost catalyst exhibits excellent catalytic activity and stability in the selective oxidation of mono-, di- and tri-substituted phenols to their corresponding p-benzoquinones, even better than the reported metal-based catalysts (e.g., yield, stability) and industrial catalysts for particular substrates. It was suggested that the zigzag configuration as a type of carbon defects may play a crucial role in these reactions by stabilizing the intermediate phenoxy radicals. The phosphate or borate (P_xO_y, B_xO_y)-modified URNM exhibits the enhanced selectivity in dehydrogenation reactions. The results reveal that P_xO_y or B_xO_y preferentially reacts with the oxygen groups initially present on the URNM surface, and then it selectively blocks the defect sites that lead to CO_x formation with an increased propene selectivity.Moreover, we have also demonstrated that the introduction of heteroatoms (B, P, N) into URCM imparts remarkable properties that allow it to act as novel and stable catalysts in improving the catalytic activity for oxygen reduction in electrochemical field. Meanwhile, the stabilization of palladium nanoparticles on buckdiamond supports has been reported for the first time. The obtained catalysts exhibit the excellent catalytic performance for CO oxidation. The related articles can be found in the following:

ACS Catalysis 5(2015) 5921、ACS Catalysis 5(2015) 2436、Chemical Communications 51(2015) 9145、Chemical Communications 51(2015) 13086、Journal of Materials Chemistry A 3(2015) 21805、Journal of Materials Chemistry A 3(2015) DOI: 10.1039/C5TA09539E、ChemSusChem 8(2015) 2872、ChemCatChem 7(2015) 2840、Angewandte Chemie International Edition (2015) DOI: 10.1002/anie.201507821

Patent number：201510154630.9.

Figure 1. Catalytic oxidation of various substituted phenols over onion-like carbon.

Key Words: Diamond, Metal-free, Catalysis, Energy

Contact:
Associated Dr. LIN Yangming
Email: ymlin12b@imr.ac.cn
Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, Liaoning, 110016, China