Single cobalt sites in mesoporous N-doped carbon matrix for selective catalytic hydrogenation of nitroarenes
Type
ArticleAuthors
Sun, XiaohuiOlivos-Suarez, Alma I.
Osadchii, Dmitrii
Romero, Maria Jose Valero
Kapteijn, Freek

Gascon, Jorge

KAUST Department
Chemical Engineering ProgramKAUST Catalysis Center (KCC)
Physical Science and Engineering (PSE) Division
Date
2017-11-20Online Publication Date
2017-11-20Print Publication Date
2018-01Permanent link to this record
http://hdl.handle.net/10754/626185
Metadata
Show full item recordAbstract
A supported cobalt catalyst with atomically dispersed Co-Nx sites (3.5 wt% Co) in a mesoporous N-doped carbon matrix (named Co@mesoNC) is synthesized by hydrolysis of tetramethyl orthosilicate (TMOS) in a Zn/Co bimetallic zeolitic imidazolate framework (BIMZIF(Co,Zn)), followed by high-temperature pyrolysis and SiO2 leaching. A combination of TEM, XRD XPS and X-ray absorption spectroscopy studies confirm the absence of cobalt nanoparticles and indicate that these highly dispersed cobalt species are present in the form of Co-Nx. The exclusive formation of Co-Nx sites in the carbon matrix is attributed to the presence of a large amount of Zn and N in the BIMZIF precursor together with the presence of SiO2 in the pore space of this framework, extending the initial spatial distance between cobalt atoms and thereby impeding their agglomeration. The presence of SiO2 during high-temperature pyrolysis is proven crucial to create mesoporosity and a high BET area and pore volume in the N-doped carbon support (1780 m2 g−1, 1.54 cm3 g−1). This heterogeneous Co@mesoNC catalyst displays high activity and selectivity (>99%) for the selective hydrogenation of nitrobenzene to aniline at mild conditions (0.5–3 MPa, 343–383 K). When more challenging substrates (functionalized nitroarenes) are hydrogenated, the catalyst Co@mesoNC displays an excellent chemoselectivity to the corresponding substituted anilines.The presence of mesoporosity improves mass transport of reactants and/or products and the accessibility of the active Co-Nx sites, and greatly reduces deactivation due to fouling.Citation
Sun X, Olivos-Suarez AI, Osadchii D, Romero MJV, Kapteijn F, et al. (2018) Single cobalt sites in mesoporous N-doped carbon matrix for selective catalytic hydrogenation of nitroarenes. Journal of Catalysis 357: 20–28. Available: http://dx.doi.org/10.1016/j.jcat.2017.10.030.Sponsors
We thank for the support from the Dutch-Belgian program for access to the BM26A in ESRF, Grenoble. We thank A. Dikhtiarenko for help in the design of the graphical abstract. Xiaohui Sun acknowledges financial support from China Scholarship Council (CSC).Publisher
Elsevier BVJournal
Journal of CatalysisAdditional Links
http://www.sciencedirect.com/science/article/pii/S0021951717303901ae974a485f413a2113503eed53cd6c53
10.1016/j.jcat.2017.10.030