Inquiry2015-2

“The pores in these particles force molecules to move in

different ways, and we need to know more about that in order

to optimize these catalytic systems to work the most efficiently.”

NMR spectroscopy

“Honestly, wi thout Marek we ’ d be fly ing

bl ind.”

– Aaron Sadow

Marek Pruski’s group provides guidance to other project

members with the structural insights. To do so, Pruski

uses Ames Laboratory’s state-of-the-art solid-state NMR

instrumentation, including the recently acquired dynamic

nuclear polarization (DNP) NMR spectrometer, the first

in the nation to be used exclusively for materials science

research. Its use represents up to a 300-fold increase in

sensitivity and a “transformational” technique in providing

information to experimental researchers and theorists.

“No other method of spectroscopy can probe the structure

of materials with such atomic-level sensitivity to the local

electronic environment,” said Pruski. “Until you carry out

proper characterization of a catalyst, you can only make

educated guesses about what the structure might be. It’s one

of the unique strengths of this program that we can provide

a very thorough characterization of catalysts as we build and

use them.”

That’s helped guide experimentalists Sadow and

Slowing work towards common research goals, refining

the designs of both the mesoporous structures and the

catalysts themselves.

“Honestly, without Marek we’d be flying blind,” said

Sadow.

“We of course want these systems to work well, to be

useful, but we also want to understand how they work,” said

Pruski. “If we can achieve that understanding, we can engage

in a rational design of catalytic systems rather than rely on

serendipity.”

Theorist

“We try to help them figure out what exactly

happens in the middle . I t ’ s a way of ver i fy ing

a n d u n d e r s t a n d i n g t h e i r e x p e r i me n t a l

results . ”

– Theresa Windus

Three theorists have contributed their computational

modeling expertise in order to better understand the systems

the experimentalists are designing.

One of them, Theresa Windus, an Ames Laboratory

associate in chemistry, has provided Sadow with computer

models of the reaction mechanisms of the catalysts he and

Slowing are building.

“They have their catalyst, and their reactants and

end products, but they can’t really see the reaction

itself occurring. We try to help them figure out what

exactly happens in the middle. It’s a way of verifying and

understanding their experimental results, infrared and

NMR spectra,” said Windus.

Many times, said Windus, it begins with a dialogue.

“They’ll ask us to verify some experimental result, and after

doing the computations, we’ll realize that we’re not getting

what they think we should. Then we go back to them and

ask ‘is there another explanation for what’s happening?’ It

becomes a very synergistic information loop.”

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Inqui r y I s sue 2 | 2015

Additionally, Ames Laboratory associate Jim Evans

has provided Igor Slowing kinetic models describing how

molecules move within the nanopores of the materials, and

Ames Laboratory associate Mark Gordon has contributed to

the group with molecular modeling of chemical processes

on the surfaces of the materials.

Taken altogether, Sadow considers the contribution of

the three an asset to the experimental side.

“I think that you can force systems to behave in certain

ways,and ask questions about them in theory that you really

cannot ask in an experiment,” said Sadow. “That helps us

consider different possible pathways to the same result, and

which one best describes what’s actually happening.”

World-class catalysis research

“A s ingle person cannot real i st ically have

all the sk i lls needed to fully interrogate

matter . You need many people , many sk i lls . ”

– Igor Slowing

Ames Laboratory’s combination of catalysis, spectroscopy

and theoretical experts creates a widely respected research

reputation in a field that has far-reaching impact in industrial,

environmental and medical applications.

“When I first began my research group’s work, I only

felt comfortable proposing research that I individually had

the skill set to accomplish,” Sadow said. “That’s always the

individual’s limitation. With others’ contributions, the scope

of what kind of problem you can tackle becomes much

greater, and that’s the great appeal of our research group.”

Windus considers it personally gratifying to have impact

on disciplines outside her own area of expertise. “Catalysts

are a lot of fun,” she said. “They are amazing compounds

that make perfectly impractical reactions viable, useful and

doable, and I enjoy making contributions to applied science.”

And in a broader sense, Slowing believes collaboration is

also fundamental to success in today’s research world.

“It’s a huge value, the way science is right now. You can

try to master as many different things as you can, but a single

person cannot realistically have all the skills needed to fully

interrogate matter. You need as many different specialists in

as many diverse areas as possible to be successful.”

According to Pruski, Ames Laboratory has continued to

lead in the field of catalysis because of the synergistic efforts

of world-class researchers.

“We don’t work together just because we all happen to

be here in one place. The synergy of this program is truly

vital, and real.”

Chemist2 + NMR Spectroscopy +Theorist3 =World-class Catalysis Research