{"id":17637,"date":"2013-10-29T02:05:30","date_gmt":"2013-10-29T00:05:30","guid":{"rendered":"https:\/\/renewable-carbon.eu\/news\/?p=17637"},"modified":"2013-10-28T17:57:05","modified_gmt":"2013-10-28T15:57:05","slug":"gold-nanoparticles-give-edge-recycling-co2","status":"publish","type":"post","link":"https:\/\/renewable-carbon.eu\/news\/gold-nanoparticles-give-edge-recycling-co2\/","title":{"rendered":"Gold nanoparticles give an edge in recycling CO2<\/sub>"},"content":{"rendered":"

Researchers from Brown have shown that finely tuned gold nanoparticles can do the job. The key is maximizing the particles\u2019 long edges, which are the active sites for the reaction.<\/p>\n

By tuning gold nanoparticles to just the right size, researchers from Brown University have developed a catalyst that selectively converts carbon dioxide (CO2<\/sub>) to carbon monoxide (CO), an active carbon molecule that can be used to make alternative fuels and commodity chemicals.<\/p>\n

\u201cOur study shows potential of carefully designed gold nanoparticles to recycle CO2<\/sub> into useful forms of carbon,\u201d said Shouheng Sun, professor of chemistry and one of the study\u2019s senior authors. \u201cThe work we\u2019ve done here is preliminary, but we think there\u2019s great potential for this technology to be scaled up for commercial applications.\u201d<\/p>\n

The findings are published in the Journal of the American Chemical Society<\/a>.<\/p>\n

The idea of recycling CO2<\/sub> \u2014 a greenhouse gas the planet current has in excess \u2014 is enticing, but there are obstacles. CO2<\/sub> is an extremely stable molecule that must be reduced to an active form like CO to make it useful. CO is used to make synthetic natural gas, methanol, and other alternative fuels.<\/p>\n

Converting CO2<\/sub> to CO isn\u2019t easy. Prior research has shown that catalysts made of gold foil are active for this conversion, but they don\u2019t do the job efficiently. The gold tends to react both with the CO2<\/sub> and with the water in which the CO2<\/sub> is dissolved, creating hydrogen byproduct rather than the desired CO.<\/p>\n

The Brown experimental group, led by Sun and Wenlei Zhu, a graduate student in Sun\u2019s group, wanted to see if shrinking the gold down to nanoparticles might make it more selective for CO2<\/sub>. They found that the nanoparticles were indeed more selective, but that the exact size of those particles was important. Eight nanometer particles had the best selectivity, achieving a 90-percent rate of conversion from CO2<\/sub> to CO. Other sizes the team tested \u2014 four, six, and 10 nanometers \u2014 didn\u2019t perform nearly as well.<\/p>\n

\u201cAt first, that result was confusing,\u201d said Andrew Peterson, professor of engineering and also a senior author on the paper. \u201cAs we made the particles smaller we got more activity, but when we went smaller than eight nanometers, we got less activity.\u201d<\/p>\n

To understand what was happening, Peterson and postdoctoral researcher Ronald Michalsky used a modeling method called density functional theory. They were able to show that the shapes of the particles at different sizes influenced their catalytic properties.<\/p>\n

\u201cWhen you take a sphere and you reduce it to smaller and smaller sizes, you tend to get many more irregular features \u2014 flat surfaces, edges and corners,\u201d Peterson said. \u201cWhat we were able to figure out is that the most active sites for converting CO2<\/sub> to CO are the edge sites, while the corner sites predominantly give the by-product, which is hydrogen. So as you shrink these particles down, you\u2019ll hit a point where you start to optimize the activity because you have a high number of these edge sites but still a low number of these corner sites. But if you go too small, the edges start to shrink and you\u2019re left with just corners.\u201d<\/p>\n

Now that they understand exactly what part of the catalyst is active, the researchers are working to further optimize the particles. \u201cThere\u2019s still a lot of room for improvement,\u201d Peterson said. \u201cWe\u2019re working on new particles that maximize these active sites.\u201d<\/p>\n

The researchers believe these findings could be an important new avenue for recycling CO2<\/sub> on a commercial scale.<\/p>\n

\u201cBecause we\u2019re using nanoparticles, we\u2019re using a lot less gold than in a bulk metal catalyst,\u201d Sun said. \u201cThat lowers the cost for making such a catalyst and gives the potential to scale up.\u201d<\/p>\n

The work was funded by a National Science Foundation grant to the Brown-Yale Center for Chemical Innovation (CCI), which looks for ways to use CO2<\/sub> as a sustainable feedstock for large-scale commodity chemicals. Other authors on the paper were \u00d6nder Metin, Haifeng Lv, Shaojun Guo, Christopher Wright, and Xiaolian Sun.<\/p>\n","protected":false},"excerpt":{"rendered":"

Researchers from Brown have shown that finely tuned gold nanoparticles can do the job. The key is maximizing the particles\u2019 long edges, which are the active sites for the reaction. By tuning gold nanoparticles to just the right size, researchers from Brown University have developed a catalyst that selectively converts carbon dioxide (CO2) to carbon […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","nova_meta_subtitle":"","footnotes":""},"categories":[5572],"tags":[],"supplier":[4503,5825,1144],"class_list":["post-17637","post","type-post","status-publish","format-standard","hentry","category-bio-based","supplier-brown-university","supplier-brown-yale-center-for-chemical-innovation","supplier-national-science-foundation-usa"],"_links":{"self":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/17637","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/comments?post=17637"}],"version-history":[{"count":0,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/17637\/revisions"}],"wp:attachment":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media?parent=17637"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/categories?post=17637"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/tags?post=17637"},{"taxonomy":"supplier","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/supplier?post=17637"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}