Catalyst for a greener future
Date:
March 16, 2022
Source:
University of Delaware
Summary:
Researchers have found a way to improve the ability of catalysts
made from metal-metal oxides to convert non-edible plants, such
as wood, grass and corn stover into renewable fuels, chemicals
and plastics. Metal oxide catalysts are central to reactions
for upgrading petrochemicals, fine chemicals, pharmaceuticals
and biomass.
FULL STORY ========================================================================== Catalysts are workhorses that help reactions occur. Put to work, they
transform starting materials, such as fossil fuels, biomass or even waste,
into products and fuels with minimal energy.
========================================================================== Researchers in the Catalysis Center for Energy Innovation (CCEI) at
the University of Delaware have found a way to improve the ability of
catalysts made from metal-metal oxides to convert non-edible plants, such
as wood, grass and corn stover -- the leaves, stalks and cobs leftover in
the fields after harvest -- into renewable fuels, chemicals and plastics.
Metal-metal oxide catalysts are central to reactions for upgrading petrochemicals, fine chemicals, pharmaceuticals and biomass.
The research team's strategy capitalized on the dynamic nature of
platinum- tungsten oxide catalysts to convert these starting materials
into products up to 10 times faster than traditional methods. It's the
type of innovative catalytic technology that could help usher in a more sustainable and greener future, where processes require less catalyst
to operate, leading to less waste and less overall energy use.
The CCEI researchers reported their findings in Nature Catalysis on
Feb. 21.
Boosting catalyst activity The surface of a catalyst contains multiple
active sites at which chemical reactions occur. These active sites
are sensitive and dynamic, changing in response to their environment
in highly complex and often difficult-to-predict ways. As a result,
little is known about how processes on these active sites operate or
how the sites interact with their surroundings. Traditional approaches
for increasing understanding, such as studying catalysts under static conditions in a chemical reactor, don't work.
==========================================================================
So CCEI researchers combined modeling, advanced synthetic techniques,
in-situ spectroscopies and probe reactions to get a better look at
how platinum and tri-tungsten oxide catalyst materials come together,
what structure they take and what happens on the catalyst's surface. In particular, the research team was interested in how the active sites
on a catalyst (where the chemical reactions occur) evolve over time and
when exposed to specific changes.
"By identifying the telltale signs of their dynamics, we were able to establish, for the first time, a robust model to predict their behavior
in various working environments," said Jiayi Fu, the paper's lead author,
who recently earned his UD doctoral degree in chemical engineering and
now works at Bristol Myers Squibb.
Fu explained that catalyst surfaces -- like plants -- flourish when
given the proper balance of sunshine and sustenance. The research team successfully demonstrated a novel "irrigation" strategy which uses
hydrogen pulsing to significantly increase the population of active
sites on these catalysts, allowing reactions to occur 10 times faster.
"We're not actually watering the catalysts, that's just a metaphor. But,
by pulsing hydrogen gas on and off, we create these active sites that
mimic water, through a process known as hydroxylation," said Dion
Vlachos, the Unidel Dan Rich Chair in Energy, professor of chemical and biomolecular engineering and director of CCEI. "These active sites then
do the chemistry. So, like light and water feeds the plants, here we
feed hydrogen to 'water' the catalyst and make it produce -- or grow
-- new chemicals." The work illustrates a successful example of how simulations can predict catalytic behavior and enable the rational design
of more efficient catalytic processes, said Vlachos, who also directs
the Delaware Energy Institute. The findings also provide a viable way
to study, understand and control this important class of catalysts.
"Catalysts are known to evolve and respond to their environment, but they
do this quickly, in ways that have been hard to observe in real time,"
he said.
"This work sets a platform for how to dissect their working behavior
and, importantly, how to engineer them for unprecedented performance enhancement." The UD-led project team at CCEI included researchers
from the University of Delaware, the University of Pennsylvania, the
University of Massachusetts Amherst, Brookhaven National Laboratory,
Stony Brook University, Tianjin University, Dalian Institute of Chemical Physics and Shanghai Jiao Tong University.
Founded in 2009, the Catalysis Center for Energy Innovation is one of
two Energy Frontier Research Centers funded at UD by the U.S. Department
of Energy.
The center is comprised of researchers from multiple universities and
the Brookhaven National Laboratory.
========================================================================== Story Source: Materials provided by University_of_Delaware. Original
written by Karen B.
Roberts. Note: Content may be edited for style and length.
========================================================================== Journal Reference:
1. Jiayi Fu, Shizhong Liu, Weiqing Zheng, Renjing Huang, Cong Wang,
Ajibola
Lawal, Konstantinos Alexopoulos, Sibao Liu, Yunzhu Wang, Kewei
Yu, J.
Anibal Boscoboinik, Yuefeng Liu, Xi Liu, Anatoly I. Frenkel, Omar A.
Abdelrahman, Raymond J. Gorte, Stavros Caratzoulas, Dionisios
G. Vlachos.
Modulating the dynamics of Bro/nsted acid sites on PtWOx
inverse catalyst. Nature Catalysis, 2022; 5 (2): 144 DOI:
10.1038/s41929-022- 00745-y ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2022/03/220316132703.htm
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