Xinming Hu: Metal and Nitrogen Doped Porous Carbon Electrocatalysts for CO2 Reduction

posted 14 Jun 2017, 00:48 by Peter Boggild
Xin-Ming Hu, Halvor H. Hval, Steen U. Pedersen, and Kim Daasbjerg
Carbon Dioxide Activation Center (CADIAC), Interdisciplinary Nanoscience Center (iNANO), Aarhus University. Gustav Wieds Vej 14, 8000 Aarhus C, Denmark

Metalloporphyrins immobilized on carbon materials have been proved to be catalytically active for CO2 electroreduction in neutral water.[1-2] The porous carbon materials installed with metalloporphyrin-like structures are expected to be more promising due to their large surface area, high conductivity, and good chemical stability.[3] In this work, we prepared a series of transition metal and nitrogen co-doped carbon materials (M-N-C) via silica-templated pyrolysis. The resulting M-N-C features porous and metalloporphyrin-like structures. Of the materials studied, the Ni-N-C exhibits the highest Faradiac efficiency (91%) for CO2-to-CO conversion at an overpotential of 450 mV, while the Fe-N-C shows the highest current density (3.5 mA cm^-2) associated with a decent Faradiac efficiency (81%) for CO production. The acid leaching and cyanide poisoning experiments verify that the atomically dispersed metal centers embedded in the carbon platform are the origin of the catalytic activity. Importantly, the performance of the M-N-C electrocatalyst for CO2 reduction differs substantially from that of the corresponding metalloporphyrin immobilized on carbon materials. This may be attributed to the different coordination environment of the metal in M-N-C compared with that of the molecular metalloporphyrin.

1. Maurin, A.; Robert, M. J. Am. Chem. Soc. 2016, 138, 2492−2495.
2. Hu, X.-M.; Rønne, M. H.; Pedersen, S. U.; Skrydstrup, T.; Daasbjerg, K. Angew. Chem. Int. Ed. 2017, 56, 6468-6472.
3. Liang, H. W.; Bruller, S.; Dong, R. H.; Zhang, J.; Feng, X. L.; Mullen, K. Nat. Commun. 2015, 6, 7992.

Xinming Hu is currently a postdoctoral fellow at Carbon Dioxide Activation Center (CADIAC), Interdisciplinary Nanoscience Center (iNANO), Aarhus University. His research interest is to explore porous and/or surface-attached materials for electrocatalytic CO2 reduction. He received his B.S. degree (2008) in Environmental Science from Nankai University, M.S. degree (2011) in Chemistry from University of Chinese Academy of Sciences, and Ph.D. (2014) in Chemistry from University of Copenhagen where he focused on the synthesis of porous materials for gas adsorption.