From DOE’s Brookhaven National Laboratory (US): “Steering Conversion of CO2 and Ethane to Desired Products”
From DOE’s Brookhaven National Laboratory (US)
February 9, 2022
kmcnulty@bnl.gov
Karen McNulty Walsh
(631) 344-8350
Peter Genzer
genzer@bnl.gov
(631) 344-3174
Study IDs key catalytic features that drive reaction specificity when transforming CO2 (a greenhouse gas) and an underutilized component of natural gas into higher-value chemicals.
Zhenhua Xie, a research associate in Brookhaven Lab’s Chemistry Division, holds precursor solutions for the synthesis of catalysts. He is first author on a paper describing the characteristics of a particular catalyst that determine its selectivity for converting CO2 and ethane to either syngas or ethylene.
Converting carbon dioxide (CO2) and ethane—an underutilized component of natural gas—into things we need would be a great way to put a potent greenhouse gas and an unused reservoir of hydrocarbons to work. But driving such reactions specifically toward one desired product or another can be a challenge. Discovering the underlying principles that determine the behavior of catalysts—the chemical “deal makers” that bring reactants together—could provide the key to more selective reactions.
In a study just published in the Journal of the American Chemical Society, chemists from the U.S. Department of Energy’s Brookhaven National Laboratory, Columbia University (US), and The University at Binghampton-(SUNY)(US) describe the features that determine catalytic selectivity for one set of reactions: transforming CO2 and ethane (C2H6) into synthesis gas (useful for generating electricity or making liquid fuels) or, alternatively, ethylene (a building block for making paints, plastics, and other polymers).
“Both pathways are valuable, but you want to be able to drive the reaction selectively to one or the other to make it easier and more economical to extract the desired product,” said Jingguang Chen, a chemist with a joint appointment at Brookhaven and Columbia who led the research. “We were trying to identify the key catalytic principles that make it select one pathway or another, with the idea that these principles could then guide the design of catalysts for an even wider range of reactions.”
To discover the key principles, the team conducted detailed studies of a series of bimetallic (two-metal) catalysts—using different metals paired with palladium. For each combination, they examined how the metals come together and measured how the mix of reactants and products changes during the reaction.
This schematic shows two possible reaction pathways for carbon dioxide (CO2) with ethane (C2H6), where carbon is black, oxygen is red, hydrogen is white. By studying catalysts pairing another metal with palladium, scientists identified two arrangements, or phases, that determine the reaction pathway. Top: If the metals form an alloy, the catalyst favors breaking carbon-carbon bonds to produce carbon monoxide and hydrogen gas—syngas. Bottom: If the metals segregate to form an oxide interface, the catalyst favors breaking carbon-hydrogen bonds and produces ethylene (C2H4), carbon monoxide, and water.
They also studied the catalysts’ atomic structures and electronic properties using powerful x-rays at the National Synchrotron Light Source II (NSLS-II)[below] and the Advanced Photon Source—two DOE Office of Science user facilities at Brookhaven and The DOE’s Argonne National Laboratory(US), respectively.
ANL DOE Argonne National Laboratory (US) Advanced Photo Source.
And they ran computational modeling studies using computing clusters at Brookhaven’s Center for Functional Nanomaterials and supercomputers at The DOE’s NERSC National Energy Research Scientific Computing Center(US) at DOE’s Lawrence Berkeley National Laboratory (US)—two more DOE Office of Science user facilities.
The modeling studies used “density functional theory” (DFT) to predict how the arrangement of atoms that make up the catalyst changes as the reaction progresses, based on things like the binding energies between different sets of atoms and the energies needed to break and remake chemical bonds.
“For both theory and experiment, we looked not just at the catalyst samples as they were originally prepared, but also as they undergo phase transformations during the reaction,” said Ping Liu, an expert in DFT calculations in the Catalysis Reactivity and Structure group of Brookhaven’s Chemistry Division.
“When we put two metals together,” Chen explained, “they stay in one structure we call a bulk alloy. But under reaction conditions, when you expose the catalyst to CO2 and ethane, those metals start to move. This is why a synchrotron like NSLS-II is really critical, because the high intensity photon source allows us to measure the electronic and physical structures of the active sites under reaction conditions,” he said.
“The strong interaction among techniques—including controlled catalytic synthesis, synchrotron-based characterization studies, kinetic measurements, and theoretical modeling—was essential for this study, ” Liu said.
Chen agreed. “Without any one of these techniques, we would not have reached our conclusions. And we can only really do this in a national laboratory setting where there are facilities and expertise across all these areas,” he said.
So, what were those conclusions? The discovery of two key principles, or descriptors, that determine whether and how the metal atoms move, and how those shifts drive reaction selectivity.
The key principles are: 1) the “formation energy” of the bimetallic catalyst—how tightly bound together the two metals are, and 2) the binding energy between the catalyst and oxygen released from the CO2 during the reaction.
If the two metals are bound together strongly (e.g., when palladium is paired with cobalt), the catalyst won’t bind with the freed oxygen and will remain an alloy, as shown in the top half of the illustration. This catalytic arrangement favors the breaking of carbon-carbon bonds, selectively transforming CO2 and ethane into carbon monoxide and hydrogen gas—the components of syngas.
But if the catalyst’s affinity for freed oxygen is strong enough to overcome the formation energy of the alloy—as is the case for palladium paired with indium—the paired metal will move to the surface of the catalyst to form an oxide shell. That configuration favors breaking carbon-hydrogen bonds, driving the pathway that produces ethylene.
The other metals the scientists paired with palladium fell somewhere between these two extremes. Scientists used the full dataset to extract the two key principles.
“By using the descriptors we’ve identified, now we can help guide the design of catalysts for either pathway—to make either syngas or ethylene,” Chen said.
In addition, as Liu pointed out, “these are generalized descriptors, which means they are not only applicable for one or two specific catalysts. Our experiments and theory prove that this approach works for the palladium-based catalysts. We think that could be extended for other bimetallic catalysts, which is something we will be looking at in the future.
Zhenhua Xie and Xuelong Wang (both of Brookhaven Lab) and Xiaobo Chen (Binghamton) were additional co-authors on this study. The work was funded by the DOE Office of Science (BES).
See the full article here .
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One of ten national laboratories overseen and primarily funded by the DOE(US) Office of Science, DOE’s Brookhaven National Laboratory (US) conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University(US), the largest academic user of Laboratory facilities, and Battelle(US), a nonprofit, applied science and technology organization.
Research at BNL specializes in nuclear and high energy physics, energy science and technology, environmental and bioscience, nanoscience and national security. The 5,300 acre campus contains several large research facilities, including the Relativistic Heavy Ion Collider [below] and National Synchrotron Light Source II [below]. Seven Nobel prizes have been awarded for work conducted at Brookhaven lab.
BNL is staffed by approximately 2,750 scientists, engineers, technicians, and support personnel, and hosts 4,000 guest investigators every year. The laboratory has its own police station, fire department, and ZIP code (11973). In total, the lab spans a 5,265-acre (21 km^2) area that is mostly coterminous with the hamlet of Upton, New York. BNL is served by a rail spur operated as-needed by the New York and Atlantic Railway. Co-located with the laboratory is the Upton, New York, forecast office of the National Weather Service.
Major programs
Although originally conceived as a nuclear research facility, Brookhaven Lab’s mission has greatly expanded. Its foci are now:
Nuclear and high-energy physics
Physics and chemistry of materials
Environmental and climate research
Nanomaterials
Energy research
Nonproliferation
Structural biology
Accelerator physics
Operation
Brookhaven National Lab was originally owned by the Atomic Energy Commission(US) and is now owned by that agency’s successor, the United States Department of Energy (DOE). DOE subcontracts the research and operation to universities and research organizations. It is currently operated by Brookhaven Science Associates LLC, which is an equal partnership of Stony Brook University(US) and Battelle Memorial Institute(US). From 1947 to 1998, it was operated by Associated Universities, Inc. (AUI) (US), but AUI lost its contract in the wake of two incidents: a 1994 fire at the facility’s high-beam flux reactor that exposed several workers to radiation and reports in 1997 of a tritium leak into the groundwater of the Long Island Central Pine Barrens on which the facility sits.
Foundations
Following World War II, the US Atomic Energy Commission was created to support government-sponsored peacetime research on atomic energy. The effort to build a nuclear reactor in the American northeast was fostered largely by physicists Isidor Isaac Rabi and Norman Foster Ramsey Jr., who during the war witnessed many of their colleagues at Columbia University leave for new remote research sites following the departure of the Manhattan Project from its campus. Their effort to house this reactor near New York City was rivalled by a similar effort at the Massachusetts Institute of Technology (US) to have a facility near Boston, Massachusettes(US). Involvement was quickly solicited from representatives of northeastern universities to the south and west of New York City such that this city would be at their geographic center. In March 1946 a nonprofit corporation was established that consisted of representatives from nine major research universities — Columbia University(US), Cornell University(US), Harvard University(US), Johns Hopkins University(US), Massachusetts Institute of Technology(US), Princeton University(US), University of Pennsylvania(US), University of Rochester(US), and Yale University(US).
Out of 17 considered sites in the Boston-Washington corridor, Camp Upton on Long Island was eventually chosen as the most suitable in consideration of space, transportation, and availability. The camp had been a training center from the US Army during both World War I and World War II. After the latter war, Camp Upton was deemed no longer necessary and became available for reuse. A plan was conceived to convert the military camp into a research facility.
On March 21, 1947, the Camp Upton site was officially transferred from the U.S. War Department to the new U.S. Atomic Energy Commission (AEC), predecessor to the U.S. Department of Energy (DOE).
Research and facilities
Reactor history
In 1947 construction began on the first nuclear reactor at Brookhaven, the Brookhaven Graphite Research Reactor. This reactor, which opened in 1950, was the first reactor to be constructed in the United States after World War II. The High Flux Beam Reactor operated from 1965 to 1999. In 1959 Brookhaven built the first US reactor specifically tailored to medical research, the Brookhaven Medical Research Reactor, which operated until 2000.
Accelerator history
In 1952 Brookhaven began using its first particle accelerator, the Cosmotron. At the time the Cosmotron was the world’s highest energy accelerator, being the first to impart more than 1 GeV of energy to a particle.
The Cosmotron was retired in 1966, after it was superseded in 1960 by the new Alternating Gradient Synchrotron (AGS).
BNL Alternating Gradient Synchrotron (AGS).
The AGS was used in research that resulted in 3 Nobel prizes, including the discovery of the muon neutrino, the charm quark, and CP violation.
In 1970 in BNL started the ISABELLE project to develop and build two proton intersecting storage rings.
The groundbreaking for the project was in October 1978. In 1981, with the tunnel for the accelerator already excavated, problems with the superconducting magnets needed for the ISABELLE accelerator brought the project to a halt, and the project was eventually cancelled in 1983.
The National Synchrotron Light Source (US) operated from 1982 to 2014 and was involved with two Nobel Prize-winning discoveries. It has since been replaced by the National Synchrotron Light Source II (US). [below].
BNL National Synchrotron Light Source (US).
After ISABELLE’S cancellation, physicist at BNL proposed that the excavated tunnel and parts of the magnet assembly be used in another accelerator. In 1984 the first proposal for the accelerator now known as the Relativistic Heavy Ion Collider (RHIC)[below] was put forward. The construction got funded in 1991 and RHIC has been operational since 2000. One of the world’s only two operating heavy-ion colliders, RHIC is as of 2010 the second-highest-energy collider after the Large Hadron Collider(CH). RHIC is housed in a tunnel 2.4 miles (3.9 km) long and is visible from space.
On January 9, 2020, It was announced by Paul Dabbar, undersecretary of the US Department of Energy Office of Science, that the BNL eRHIC design has been selected over the conceptual design put forward by DOE’s Thomas Jefferson National Accelerator Facility [Jlab] (US) as the future Electron–ion collider (EIC) in the United States.
Brookhaven Lab Electron-Ion Collider (EIC) (US) to be built inside the tunnel that currently houses the RHIC.
In addition to the site selection, it was announced that the BNL EIC had acquired CD-0 from the Department of Energy. BNL’s eRHIC design proposes upgrading the existing Relativistic Heavy Ion Collider, which collides beams light to heavy ions including polarized protons, with a polarized electron facility, to be housed in the same tunnel.
Other discoveries
In 1958, Brookhaven scientists created one of the world’s first video games, Tennis for Two. In 1968 Brookhaven scientists patented Maglev, a transportation technology that utilizes magnetic levitation.
Major facilities
Relativistic Heavy Ion Collider (RHIC), which was designed to research quark–gluon plasma and the sources of proton spin. Until 2009 it was the world’s most powerful heavy ion collider. It is the only collider of spin-polarized protons.
Center for Functional Nanomaterials (CFN), used for the study of nanoscale materials.
BNL National Synchrotron Light Source II(US), Brookhaven’s newest user facility, opened in 2015 to replace the National Synchrotron Light Source (NSLS), which had operated for 30 years. NSLS was involved in the work that won the 2003 and 2009 Nobel Prize in Chemistry.
Alternating Gradient Synchrotron, a particle accelerator that was used in three of the lab’s Nobel prizes.
Accelerator Test Facility, generates, accelerates and monitors particle beams.
Tandem Van de Graaff, once the world’s largest electrostatic accelerator.
Computational Science resources, including access to a massively parallel Blue Gene series supercomputer that is among the fastest in the world for scientific research, run jointly by Brookhaven National Laboratory and Stony Brook University-SUNY (US).
Interdisciplinary Science Building, with unique laboratories for studying high-temperature superconductors and other materials important for addressing energy challenges.
NASA Space Radiation Laboratory, where scientists use beams of ions to simulate cosmic rays and assess the risks of space radiation to human space travelers and equipment.
Off-site contributions
It is a contributing partner to the ATLAS experiment, one of the four detectors located at the Large Hadron Collider (LHC).
Iconic view of the European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear] [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN] ATLAS detector.
It is currently operating at The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN] near Geneva, Switzerland.
Brookhaven was also responsible for the design of the SNS accumulator ring in partnership with Spallation Neutron Source at DOE’s Oak Ridge National Laboratory (US), Tennessee.
DOE’s Oak Ridge National Laboratory(US) Spallation Neutron Source annotated.
Brookhaven plays a role in a range of neutrino research projects around the world, including the Daya Bay Neutrino Experiment (CN) nuclear power plant, approximately 52 kilometers northeast of Hong Kong and 45 kilometers east of Shenzhen, China.
Daya Bay Neutrino Experiment (CN) nuclear power plant, approximately 52 kilometers northeast of Hong Kong and 45 kilometers east of Shenzhen, China.
FNAL DUNE LBNF (US) from FNAL to Sanford Underground Research Facility, Lead, South Dakota, USA
BNL Center for Functional Nanomaterials.
BNL National Synchrotron Light Source II(US).
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