New insight into the conversion of methane to ethane by palladium-based catalysts

As part of CENTC's continuing attempts to develop catalytic processes to utilize methane gas as a potential source of fuel and other chemicals, CENTC investigators James Mayer (University of Washington) and Melanie Sanford (University of Michigan) have reported a better understanding of the way certain palladium-based catalysts release methane to form ethane. The studies, conducted collaboratively by the Mayer and Sanford research groups, were reported as a Communication in the Journal of the American Chemical Society (JACS) on October 13, 2009.

Sanford and Mayer investigated the ferrocenium-induced elimination of palladium-bound CH₃ to give ethane in order to determine which of three possible pathways was a likely route for the reaction to take. A series of experiments were carried out that suggested the reaction did not involve methyl radicals and did involve a Pd(IV) intermediate. Further reactions were carried out at low temperature (-80° C) and the Pd(IV) intermediate was observed by nuclear magnetic resonance (NMR) spectroscopy. Additional experiments with other oxidants suggested that Ag⁺ follows a similar mechanism but benzoquinone behaves differently.

The studies conducted by Mayer and Sanford are part of an ongoing project by CENTC researchers to develop catalysts for the direct oxidative dimerization or oligomerization of methane. The overall goal of this project is to address the need to form higher alkanes from methane via processes that do not involve energy-intensive cracking or steam reforming to syngas.

"Oxidatively Induced Reductive Elimination from (^tBu₂bpy)Pd(Me)₂: Palladium(IV) Intermediates in a One-Electron Oxidation Reaction" Michael P. Lanci, Matthew S. Remy, Werner Kaminsky, James M. Mayer and Melanie S. Sanford, J. Am. Chem. Soc., 2009, 131 (43), pp 15618-15620

[DOI: 10.1021/ja905816q]

Read the JACS Communication

Melanie Sanford Named Esquire Magazine's Chemist of the Year

CENTC investigator Melanie Sanford has been named Chemist of the Year in the December 2009 issue of Esquire Magazine. The article (pg. 163) touts Prof. Sanford as "a one-woman special-ops unit called in by chemical and drug companies to break down and put together molecules at her whim." Esquire goes on to describe her National Science Foundation-funded efforts "to convert methane - an abundant natural gas that's usefulness is limited because it's difficult to transport - into a petroleum-like fuel. If she succeeds, she will effectively double the world's fuel supply for pennies."

Alan Goldman and New Rutgers "Signature" Energy Course Benefit from CENTC Outreach Experience

CENTC investigator Alan Goldman (Rutgers University) recently co-created a new "signature" course designed to introduce science to non-science majors at Rutgers. The course is focused on Energy and Climate and is co-taught by four Rutgers professors from the Departments of Marine, Earth, and Planetary Sciences, Chemistry, Civil and Environmental Engineering, and Physics. The course was reported on by the New Jersey newspaper The Star-Ledger: http://www.nj.com/news/index.ssf/2009/11/rutgers_university_introduces.html

Alan Goldman's participation in the development of the course is largely an outgrowth of his participation in CENTC's outreach program to high schools (http://depts.washington.edu/centc/education_hsvisits.htm) as well as attempts as a CENTC PI to be more engaged in outreach.

Related links:

• Rutgers University Announcement - http://sas.rutgers.edu/index.php?option=com_content&task=view&id=845&Itemid=228
• Prof. Goldman’s website - http://rutchem.rutgers.edu/?q=node/623

CENTC Undergraduate Summer Research Program Accepting Applications

Applications are now available for the CENTC Undergraduate Summer Research Program. Undergraduate fellowships are available to conduct research at a choice of CENTC’s 13 locations during the summer of 2010. The program is 10 weeks long, running from June 14, 2010 through August 20, 2010. Fellows will receive a stipend and compensation for travel and housing. For more information and to download an application, visit:

http://depts.washington.edu/centc/education_ur.htm

Melanie Sanford Receives BASF Catalysis Award 2009

CENTC investigator Melanie Sanford was recently awarded the BASF Catalysis Award 2009 for her research seeking new catalytic reactions for cleaner systems and greener processes in chemistry. Read the BASF press release here:

http://www.basf.com/group/pressrelease/P-09-442

Karen Goldberg Interviewed by EarthSky

CENTC Director Karen Goldberg was interviewed by EarthSky recently on the topic of converting methane to methanol. You can listen here or read the transcript at EarthSky:



90 Second Interview
8 Minute Interview

http://www.earthsky.org/interviewpost/energy/karen-goldberg-trying-to-make-natural-gas-more-accessible-fuel-option

Related links:
CENTC Researchers Characterize Methane-Metal Complex

CENTC Researchers Characterize Methane-Metal Complex

CENTC researchers at the University of North Carolina and the University of Washington have described the first observation of a metal complex that binds methane in solution. The finding is reported in the October 23 issue of Science. The binding of methane to a metal complex is a key first step in the selective breaking of the C-H bond in methane. While the breaking of all four C-H bonds in methane is quite easy to do (think burning natural gas to heat your stove or house), breaking just one bond has proven to be quite difficult. A few metal catalysts are known to carry out this bond activation, but they have proved to be too slow, too inefficient or too expensive for widespread industrial use. The research reported in Science gives new insight into this bond activation process. This information should be useful in the quest to formulate other catalysts that may one day lead to the easy conversion of methane into other useful chemical feedstocks and fuels. The research is directly related to CENTC’s goal to utilize methane stranded in remote areas.

The Science report describes a σ-methane complex that is shown to be quite stable in solution. This report is the first observation and full characterization of a relatively long-lived σ-methane complex in solution. Nuclear magnetic resonance (NMR) spectra of the complex were obtained by protonation of a rhodium-methyl precursor at -110 °C. The complex is observed to rapidly tumble in the coordination sphere of rhodium, exchanging free and bound hydrogens. Density functional theory calculations indicate that the complex is best described as η²-C,H methane coordination to the metal.

Geometry optimized structure of 2-CH₄+ at the PBE0/BS2 level.

The authors of the report are Wesley Bernskoetter, who participated in this project as a post-doctoral fellow with Maurice Brookhart at the University of North Carolina (he is now an Assistant Professor at Brown University),Cynthia Schauer, an Associate Professor at UNC, Karen Goldberg, a Professor at UW and Director of CENTC, and Maurice Brookhart, a Professor at UNC and a CENTC Principal Investigator.

Bernskoetter, Wesley H.; Schauer, Cynthia K.; Goldberg, Karen I.; Brookhart, Maurice “Characterization of a Rhodium(I) σ-Methane Complex in Solution” Science, 326 (5952), 2009, 553-556
DOI: 10.1126/science.1177485

Related links:

Read the Science paper
UNC press release
UW press release
RSC: Chemistry World Article

2009 CENTC Annual Meeting

The CENTC Annual Meeting took place in Seattle on September 14-15, 2009. It was attended by 68 attendees, including CENTC faculty collaborators, post-doctoral fellows, graduate students, undergraduates, staff, a NSF representative and Industrial Affiliates. Participants attended presentations and poster sessions on CENTC research and education and outreach efforts. CENTC researchers utilized the time to plan future research efforts, as well.