It seems almost every day scientists are creating new catalysts that can help capture carbon dioxide (CO2) from the air. Case in point, a new catalyst, made with self reforming crystal edges, has been developed that scientists are saying can be revolutionary in the effort to help reverse global warming.
The economical catalyst recycles greenhouse gases into ingredients that can be used in hydrogen gas, fuel, and other chemicals according to the paper published on February 14th in Science.
The paper’s author, Cafer T. Yavuz, is an Associate Professor of Chemical and Biomolecular Engineering at the Korean Advanced Institute of Science and Technology (KAIST). “We set out to develop an effective catalyst that can convert large amounts of the greenhouse gases carbon dioxide and methane without failure,” said Yavuz.
The crystal edges catalyst, which consists of nickel, magnesium, and molybdenum, can work effectively for more than a month. The scientists have eliminated the need for expensive metals like platinum and rhodium.
The team was able to speed up the rate of reaction that converts CO2 and methane into hydrogen gas. This conversion process is called “dry reforming”, which is when harmful gases like CO2 are converted enabling for the production of more useful chemicals that can be used in other applications.
Previous research studies have also used nickel because it is a much more economical product. The problem is carbon byproducts would accumulate on the surface of the catalyst, binding it and rendering it useless.
“The difficulty arises from the lack of control on scores of active sites over the bulky catalysts surfaces because any refinement procedures attempted also change the nature of the catalyst itself,” said Yavuz.
The team was able to change the composition by adding single-crystalline magnesium oxide to the nickel-molybdenum nanoparticles. They heated the ingredients with a reactive gas, this moved the nanoparticles on the surface of the crystal to seek out anchor points. This resulted in the catalyst sealing its own “high-energy active sites” and fixed the location of the nanoparticles. In other words, the crystal stopped the nickel-based catalyst from having any build-up.
Youngdong Song, a graduate student from the Department of Chemical and Biomolecular Engineering at KAIST and co-author of the paper explains: “It took us almost a year to understand the underlying mechanism, once we studied all the chemical events in detail, we were shocked.”
The researchers are calling their new catalyst Nanocatalysts on Single Crystal Edges (NOSCE). The “magnesium-oxide nanopowder comes from a finely structured form of magnesium oxide.” They’ve accomplished uniform and predictable reaction results, with the molecules binding continuously to the edge.
Of course, the team is very happy with their accomplishment, excited about how this can help other researchers. Yavuz left a final comment:
Our study solves a number of challenges the catalyst community faces. We believe the NOSCE mechanism will improve other inefficient catalytic reactions and provide even further savings of greenhouse gas emissions.
This work was supported, in part, by the Saudi-Aramco-KAIST CO2 Management Center and the National Research Foundation of Korea.
