New sponge-like material beneficial for the environment

Washington, May 18 (ANI): A team of chemists has designed a new sponge-like material that can remove mercury from polluted water, easily separate hydrogen from other gases and is a more effective catalyst than the one currently used to pull sulfur out of crude oil.

Hydrodesulfurization is a widely used catalytic chemical process that removes sulfur from natural gas and refined petroleum products, such as gasoline and diesel and jet fuels.

Without the process, which is highly optimized, people would be burning sulfur, which contributes to acid rain.

Scientists have tried to improve hydrodesulfurization, or HDS, but have made no progress. Many consider it an optimized process.

Now, the Northwestern researchers, in collaboration with colleagues at Western Washington University, report that their material is twice as active as the conventional catalyst used in HDS, while at the same time being made of the same parts.

The material, cobalt-molybdenum-sulfur, which is black, brittle and freeze-dried, is a new class of chalcogels, a family of material discovered only a few years ago at Northwestern.

Chalcogels are random networks of metal-sulfur atoms with very high surface areas.

The new chalcogel is made from common elements, is stable when exposed to air or water and can be used as a powder.

This is the first report of chalcogels being used for catalysis and gas separation.

Mercouri G. Kanatzidis, Charles E. and Emma H. Morrison, Professor of Chemistry in the Weinberg College of Arts and Sciences, and doctoral student Santanu Bag made this catalyst using a method different from that of the conventional catalyst.

The Northwestern material is a gel made of cobalt, nickel, molybdenum and sulfur that then is freeze-dried, producing a sponge-like material with a very high surface area.

It is this high surface area and the material's stability under catalytic conditions that make the cobalt-molybdenum-sulfur chalcogel so active.

The researchers also demonstrated that the new chalcogel soaks up toxic heavy metals from polluted water like no other material.

The chalcogel removed nearly 99 percent of the mercury from contaminated water containing several parts per million.

Mercury likes to bind to sulfur, and the chalcogel is full of sulfur atoms.

In addition to being a better HDS catalyst and a mercury sponge, the chalcogel also is very effective at gas separation.

The researchers showed that the material easily removes carbon dioxide (CO2) from hydrogen, an application that could be useful in the hydrogen economy. (ANI)