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futurity_sci_tech 00185.txt

#AAA BATTERY powers cheap water splitter A new device uses a regular AAA BATTERY to split water into hydrogen and oxygen. The hydrogen gas could power fuel cells in zero-emissions vehicles. The battery sends an electric current through two electrodes that split liquid water into hydrogen and oxygen gas. Unlike other water splitters that use precious-metal catalysts the electrodes in the Stanford device are made of inexpensive and abundant nickel and iron. sing nickel and iron which are cheap materials we were able to make the electrocatalysts active enough to split water at room temperature with a single 1. 5-volt batterysays Hongjie Dai a chemistry professor at Stanford university. his is the first time anyone has used non-precious metal catalysts to split water at a voltage that low. It s quite remarkable because normally you need expensive metals like platinum or iridium to achieve that voltage. n addition to producing hydrogen the new water splitter could be used to make chlorine gas and sodium hydroxide an important industrial chemical according to Dai. He and his colleagues describe the new device in a study in Nature Communications. Automakers have considered long the hydrogen fuel cell a promising alternative to the gasoline engine. Fuel cell technology is essentially water splitting in reverse. A fuel cell combines stored hydrogen gas with oxygen from the air to produce electricity which powers the car. The only byproduct is water unlike gasoline combustion which emits carbon dioxide a greenhouse gas. Most of these vehicles will run on fuel manufactured at large industrial plants that produce hydrogen by combining very hot steam and natural gas an energy-intensive process that releases carbon dioxide as a byproduct. In 2015 American consumers will finally be able to purchase fuel cell cars from Toyota and other manufacturers. Although touted as zero-emissions vehicles most of the cars will run on hydrogen made from natural gas a fossil fuel that contributes to global warming. Splitting water to make hydrogen requires no fossil fuels and emits no greenhouse gases. But scientists have yet to develop an affordable active water splitter with catalysts capable of working at industrial scales. t s been a constant pursuit for decades to make low-cost electrocatalysts with high activity and long durabilitydai says. hen we found out that a nickel-based catalyst is as effective as platinum it came as a complete surprise. tanford graduate student Ming Gong co-lead author of the study made the discovery. ing discovered a nickel-metal /nickel-oxide structure that turns out to be more active than pure nickel metal or pure nickel oxide alonedai says. his novel structure favors hydrogen electrocatalysis but we still don t fully understand the science behind it. he nickel/nickel-oxide catalyst significantly lowers the voltage required to split water which could eventually save hydrogen producers billions of dollars in electricity costs according to Gong. His next goal is to improve the durability of the device. he electrodes are fairly stable but they do slowly decay over timehe says. he current device would probably run for days but weeks or months would be preferable. That goal is achievable based on my most recent resultshe researchers also plan to develop a water splitter than runs on electricity produced by solar energy. ydrogen is an ideal fuel for powering vehicles buildings and storing renewable energy on the gridsays Dai. e re very glad that we were able to make a catalyst that s very active and low cost. This shows that through nanoscale engineering of materials we can really make a difference in how we make fuels and consume energy. dditional researchers from Oak ridge National Laboratory Stanford National Taiwan University of Science and Technology Canadian Light source Inc. and University of Tennessee contributed to the study. Principal funding came from by the Global climate and Energy project the Precourt Institute for Energy at Stanford and by the US Department of energy. Source: Stanford Universityyou are free to share this article under the Creative Commons Attribution-Noderivs 3. 0 Unported license A

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