Scientists have developed a new low-temperature catalyst for producing high-purity hydrogen gas while simultaneously using up carbon monoxide (CO). The discovery—described in a paper set to publish online in the journal Science on Thursday, June 22, 2017—could improve the performance of fuel cells that run on hydrogen fuel but can be poisoned by CO.

“This catalyst produces a purer form of hydrogen to feed into the fuel cell,” said José Rodriguez, a chemist at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory. Rodriguez and colleagues in Brookhaven’s Chemistry Division—Ping Liu and Wenqian Xu—were among the team of scientists who helped to characterize the structural and mechanistic details of the catalyst, which was synthesized and tested by collaborators at Peking University in an effort led by Chemistry Professor Ding Ma.

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When her kids were young, Tracey Woodruff, PhD, MPH, knew more than most people about environmental toxics. After all, she was a senior scientist at the Environmental Protection Agency (EPA). But even she never dreamed, as she rocked her children to sleep at night, that the plastic baby bottles she used to feed them contained toxic chemicals that could leach into the warm milk. 

Back then, in the late 1990s, it wasn’t widely known that the chemicals used in plastic sippy cups and baby bottles can potentially disrupt child development by interfering with the hormone system. That, in turn, could alter the functionality of their reproductive systems or increase their risk of disease later in their lives. 

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A team of chemists from the University of Kentucky and the Institute of Physics Research of Mar del Plata in Argentina has just reported a way to trigger a fundamental step in the mechanism of photosynthesis, providing a process with great potential for developing new technology to reduce carbon dioxide levels.

Led by Marcelo Guzman, an associate professor of chemistry in the UK College of Arts and Sciences, and Ruixin Zhou, a doctoral student working with Guzman, the researchers used a synthetic nanomaterial that combines the highly reducing power of cuprous oxide (Cu2O) with a coating of oxidizing titanium dioxide (TiO2) that prevents the loss of copper (I) ion in the catalyst. The catalyst made of Cu2O/TiO2 has the unique ability to transfer electrons for reducing the atmospheric greenhouse gas carbon dioxide (CO2) while simultaneously breaking the molecule of water (H2O). The unique feature of this catalyst for electron transfer mimics the so called “Z-scheme” mechanism from photosynthesis.

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As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton conductivity is crucial for the latter; protons, i.e. positively charged hydrogen ions, are formed from hydrogen, which is used to power the fuel cell. Empa physicist Artur Braun and Qianli Chen, a doctoral student at ETH Zurich, conducted neutron scattering experiments on the Swiss Spallation Neutron Source (SINQ) at the Paul Scherrer Institute (PSI) that document the mobility of protons in the crystal lattice. In the process, they observed that the proton movements in ceramic fuel cells obey far more complex laws than previously assumed: The movement of the protons takes place according to the so-called polaron model, as the researchers recently reported in the renowned journal Nature Communications.

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Almost 25 percent of the world’s malnourished population lives in sub-Saharan Africa (SSA), where more than 300 million people depend on maize (corn) for much of their diet. The most widely-produced crop by harvested area in SSA, maize is also highly sensitive to drought. Because maize in this region is grown largely on rainfed rather than irrigated land, any future changes in precipitation patterns due to climate change could significantly impact crop yields. Assessing the likely magnitude and locations of such yield changes in the coming decades will be critical for decision makers seeking to help their nations and regions adapt to climate change and minimize threats to food security and to rural economies that are heavily dependent on agriculture.

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