Scientists unveil nature of active site in nitrogen-doped carbon for electrocatalytic CO2 reduction

August 12, 2020

Converting CO2 to value-added chemicals driven by renewable energy is a strategy of reducing carbon emission and alleviating pressure from depleting fossil resources. Electrocatalytic CO2 reduction (CO2R) to CO is an important way for CO2 utilization since CO is widely used for chemical synthesis.

Metal-free nitrogen-doped (N-doped) carbon material possesses high conductivity and tunable electronic structure. It exhibits excellent performance for the electrocatalytic CO2R to CO. However, the active site for the reaction remains under debate due to the complexity in the N species as well as the lack of methods for controllable doping of N.

Recently, a research group led by Prof. DENG Dehui from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) unveiled the nature of the active site in N-doped carbon materials for the electrocatalytic CO2R to CO. The study was published in Cell Reports Physical Science on August 12.

Via an innovated approach of silicon dioxide nanosphere template-assisted pyrolysis of phthalocyanine, the scientists prepared a series of N-doped carbon foam catalysts with precisely controlled N-dopant types and contents.

Electrochemical tests showed that at -0.5 V versus reversible hydrogen electrode (RHE), the catalyst dominated by graphitic N (GN) dopants exhibited the highest CO Faradaic efficiency of 95%, compared with those dominated by pyridinic N (PN) or pyrrolic N (ProN) dopants.

Theoretical calculations demonstrated that the limiting potentials for CO2R to CO over the carbon atoms adjacent to the GN were significantly lower than those for the hydrogen evolution reaction (HER), which favored the electrocatalytic CO2R.

The PN site tended to be blocked by the strongly adsorbed H* and the carbon atoms neighbouring to the PN possessed lower limiting potentials for HER, while the ProN disfavored both CO2R and HER.

"Compared with the PN and ProN, the GN significantly improved the activity of the adjacent carbon atoms for the electrocatalytic CO2R to CO," said Prof. DENG.
This work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, the Strategic Priority Research Program of Chinese Academy of Sciences, the DNL Cooperation Fund, CAS, and Collaborative Innovation Center of Chemistry for Energy Materials (2011.iChEM).

Chinese Academy of Sciences Headquarters

Related Science Articles from Brightsurf:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.

Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.

Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.

Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.

World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.

PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.

Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.

Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.

Read More: Science News and Science Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to