Nanocatalyst is a gas: New formula could make fuel production better, greener

Sep 20, 2010
This is an atomic-level image of tungsten oxide nanoparticles (green circles) on zirconia support. The other circles show the less-active forms of tungsten oxide. Credit: Wu Zhou/Lehigh University

A nanoparticle-based catalyst developed at Rice University may give that tiger in your tank a little more roar.

A new paper in the details a process by Rice Professor Michael Wong and his colleagues that should help oil refineries make the process of manufacturing gasoline more efficient and better for the environment.

In addition, Wong said, it could produce higher-octane gasoline and save money for an industry in which a penny here and a penny there add millions to the bottom line.

Wong's team at Rice, in collaboration with labs at Lehigh University, the Centre for Research and Technology Hellas and the DCG Partnership of Texas, reported this month that sub-nanometer clusters of tungsten oxide lying on top of zirconium oxide are a highly efficient catalyst that turns straight-line molecules of n-pentane, one of many hydrocarbons in gasoline, into better-burning branched n-pentane.

While the catalytic capabilities of tungsten oxide have long been known, it takes nanotechnology to maximize their potential, said Wong, a Rice professor of chemical and biomolecular engineering and of chemistry.

After the initial separation of crude oil into its basic components -- including gasoline, kerosene, heating oil, lubricants and other products -- refineries "crack" (by heating) heavier byproducts into molecules with fewer that can also be made into gasoline. Catalysis, a chemical process, further refines these hydrocarbons.

That's where Wong's discovery comes in. Refineries strive to make better catalysts, he said, although "compared with the academic world, industry hasn't done much in terms of new synthesis techniques, new microscopy, new biology, even new physics. But these are things we understand in the context of nanotechnology.

"We have a way to make a better catalyst that will improve the fuels they make right now. At the same time, a lot of existing chemical processes are wasteful in terms of solvents, precursors and energy. Improving a catalyst can also make the chemical process more environmentally friendly. Knock those things out, and they gain efficiencies and save money."

Wong and his team have worked for several years to find the proper mix of active tungsten oxide nanoparticles and inert zirconia. The key is to disperse nanoparticles on the zirconia support structure at the right surface coverage. "It's the Goldilocks theory - not too much, not too little, but just right," he said. "We want to maximize the amount of these nanoparticles on the support without letting them touch.

"If we hit that sweet spot, we can see an increase of about five times in the efficiency of the catalyst. But this was very difficult to do."

No wonder. The team had to find the right chemistry, at the right high temperature, to attach particles a billionth of a meter wide to grains of zirconium oxide powder. With the right mix, the particles react with straight n-pentane molecules, rearranging their five carbon and 12 hydrogen atoms in a process called isomerization.

Now that the catalyst formula is known, making the should be straightforward for industry. "Because we're not developing a whole new process - just a component of it - refineries should be able to plug this into their systems without much disruption," Wong said.

Maximizing gasoline is important as the world develops new sources of energy, he said. "There's a lot of talk about biofuels as a significant contributor in the future, but we need a bridge to get there. Our discovery could help by stretching current fuel-production capabilities."

Explore further: Thin diamond films provide new material for micro-machines

More information: Paper: pubs.acs.org/doi/abs/10.1021/ja105519y

Related Stories

Imaging a catalyst one atom at a time

Nov 09, 2009

(PhysOrg.com) -- The catalytic processes that facilitate the production of many chemicals and fuels could become much more environmentally friendly thanks to a breakthrough achieved by researchers from Lehigh ...

Researchers shed new light on catalyzed reactions

Nov 19, 2008

Rice University scientists on the hunt for a better way to clean up the stubborn pollutant TCE have created a method that lets them watch molecules break down on the surface of a catalyst as individual chemical bonds are ...

Blueprint from the interior of a catalyst

Sep 22, 2009

Irregularities in industrial catalysts can inhibit the conversion of crude oil, Utrecht University chemists have concluded. They were the first to provide a detailed blueprint of the interior of a commercially used catalyst ...

Recommended for you

Light pulses control graphene's electrical behavior

17 hours ago

Graphene, an ultrathin form of carbon with exceptional electrical, optical, and mechanical properties, has become a focus of research on a variety of potential uses. Now researchers at MIT have found a way to control how ...

A new way to make microstructured surfaces

Jul 30, 2014

A team of researchers has created a new way of manufacturing microstructured surfaces that have novel three-dimensional textures. These surfaces, made by self-assembly of carbon nanotubes, could exhibit a ...

User comments : 0