Boron nitride and silver nanoparticles to help get rid of carbon monoxide emissions

December 12, 2018, National University of Science and Technology MISIS
The scheme of synthesizing the nanohybrid catalyst from layered boron nitride, silver nanoparticles, and polyethylene glycol. Credit: Anton S. Konopatsky et al./ Journal of Catalysis, 2018

Russian chemists from NUST MISIS have developed a new hybrid catalyst for carbon monoxide oxidation consisting of hexagonal boron nitride and silver nanoparticles. This material makes it possible to get a full conversion of carbon monoxide at only 194 degrees Celsius. As stated in the Journal of Catalysis, this temperature is nowhere near the process's record temperatures, but in the future, chemists can reduce the temperature of catalysis more by increasing the concentration of silver in the hybrid material.

Carbon monoxide (carbonous oxide) is one of the most to people, but the gas is everywhere as it is released through car engine exhaust. Catalytic converters, which oxidize the gas to non-toxic nitrogen dioxide through catalytic reactions, are typically used to get rid of cars' exhaust. However, due to the increase in the efficiency of modern engines and a decrease in the of the exhaust gases, catalysts have dramatically lost efficiency and as a result, carbon monoxide content has increased in them.

To fight this effect, chemists are actively looking for new types of catalysts for CO oxidation that can work at relatively low temperatures—around 150-200 degrees Celsius. American scientists have recently developed a for the carbon monoxide oxidation of individual platinum atoms distributed over the surface of cerium oxide. Some materials have allowed scientists to oxidize CO with a lower rate of conversion at temperatures below 100 degrees.

A group of chemists from Russia and Australia led by NUST MISIS's Professor Dmitri V. Golberg has discovered a new effective catalyst that can be used to convert carbon monoxide. Scientists had previously shown that hybrid materials based on and nanoparticles are promising for this purpose. Similar materials, where boron nitride served as a carrier matrix for metal nanoparticles of the catalyst, have also been proposed, including for carbon monoxide oxidation, but gold and platinum were previously thought to be the best metals to conduct oxidation.

The structure of the hybrid catalyst from layered boron nitride and silver nanoparticles (marked in red on the top left micrograph). Credit: Journal of Catalysis, 2018

It turns out that hybrid materials with cheaper silver nanoparticles are also a very effective catalyst. To obtain these silver nanoparticles, researchers used the decomposition reaction of silver nitrate under the effect of ultraviolet light in a solution of polyethylene glycol. This approach allows scientists to obtain monodisperse silver particles up to 10 nanometers in size, which are uniformly deposited on the surface of layered boron nitride and on the polymer matrix of polyethylene glycol.

Materials with the maximum concentration of silver nanoparticles, which amounted to about 1.4 percent by weight, turned out to be the most effective. Such a hybrid catalyst allows carbon monoxide to be oxidized to carbon dioxide at a temperature of just 194 degrees Celsius. This number is still far from record values, but according to the researchers, in the future the temperature of the catalyst's work can be reduced further by increasing the concentration of , and in particular, by transforming them from the polymer matrix to boron nitride.

However, scientists do note that the current parameters of the catalyst only make it possible to use them to clean things like factories emitting harmful emissions. In the future, by reducing the temperature of the carbon monoxide conversion, these materials can also be used to reduce the ratio of carbon monoxide in vehicle emissions.

The development of catalysts for the oxidation of carbon monoxide to carbon dioxide is relevant for the purification of harmful emissions as well as catalysts for other gas reactions—such as those to handle the decomposition of methane or to reduce dioxide to hydrocarbons. Scientists around the globe are developing these catalysts to solve a number of technological and ecological issues.

Explore further: Researchers convert CO to CO2 with a single metal atom

More information: Anton S. Konopatsky et al, Synthetic routes, structure and catalytic activity of Ag/BN nanoparticle hybrids toward CO oxidation reaction, Journal of Catalysis (2018). DOI: 10.1016/j.jcat.2018.10.016

Related Stories

Researchers convert CO to CO2 with a single metal atom

March 5, 2018

Researchers from Washington State University and Tufts University have demonstrated for the first time that a single metal atom can act as a catalyst in converting carbon monoxide into carbon dioxide, a chemical reaction ...

New catalyst for the fight against smog

January 3, 2017

TSU chemists are creating a fundamentally new silver catalyst to purify the air, capable of decomposing toxic carbon monoxide, formaldehyde and other harmful volatile substances into harmless components. This nanostructure ...

Affordable catalyst for carbon dioxide recycling

November 19, 2018

A catalyst for carbon dioxide recycling, mineral pentlandite may also be a conceivable alternative to expensive precious metal catalysts. This is the result of a study conducted by researchers from Ruhr-Universität Bochum ...

Mechanism behind platinum catalyst captured

September 8, 2017

Cars are equipped with catalysts to disarm toxic exhaust gases. Platinum plays an important role there. Leiden physicists and chemists have now for the first time seen the mechanism behind a platinum catalyst. With a fundamental ...

New catalyst turns pollutant into fuel

November 12, 2018

Rather than allow power plants and industry to toss carbon dioxide into the atmosphere, incoming Rice University assistant professor Haotian Wang has a plan to convert the greenhouse gas into useful products in a green way.

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.