"It was the carbon atom sitting next to the dopant that was responsible," said Mohammad Asadi, a UIC graduate student who is one of two first-authors of the study.
"We were very surprised at first," Asadi said.
But as they continued to characterize the reaction it became clear not only that carbon was catalyzing the reaction, but that the co-catalyst system was more efficient than silver, "showing substantial synergistic effects," Asadi said.
Bijandra Kumar, UIC research scholar and the other first-author of the paper, said the team "uncovered the hidden mechanism" of the co-catalyzed reaction, which has "opened up a lot of options for designing inexpensive and efficient catalyst system for carbon dioxide conversion."
"Further, one can imagine that using atomically-thin, two-dimensional graphene nano-sheets, which have extremely high surface area and can easily be designed with dopant atoms like nitrogen, we can develop even far more efficient catalyst systems," Kumar said.
"If the reaction happened on the dopant, we would not have much freedom in terms of structure," said Salehi-Khojin. In that case, little could be done to increase the efficiency or stability of the reaction.
But with the reaction happening on the carbon, "we have enormous freedom" to use these very advanced carbon materials to optimize the reaction, he said.
The researchers hope that their research leads to commercially viable processes for the production of syngas and even gasoline from carbon dioxide.
|Contact: Jeanne Galatzer-Levy|
University of Illinois at Chicago