{"id":8841,"date":"2014-05-01T09:55:03","date_gmt":"2014-05-01T16:55:03","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=8841"},"modified":"2014-05-05T10:38:38","modified_gmt":"2014-05-05T17:38:38","slug":"copper-catalyst-makes-room-temperature-ethanol","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/copper-catalyst-makes-room-temperature-ethanol\/","title":{"rendered":"Copper Catalyst Makes Room Temperature Ethanol"},"content":{"rendered":"

We\u2019ve written a great deal about ways of making so-called \u201cbio-fuels,\u201d those ethanol, methanol and even diesel substitutes that avoid the high toxicity and environmental harm of fossil fuels.\u00a0 Often though, these substitutes require the diversion of foodstocks or the use of exotic catalysts and high energy inputs to trigger the appropriate mechanisms.<\/p>\n

Scientists as Stanford University may have found a way to use copper, though, to make ethanol without corn or other plants.\u00a0 They\u2019ve \u201ccreated a copper-based catalyst that produces large quantities of ethanol from carbon monoxide gas at room temperature.\u201d<\/p>\n

Matthew W. Kanan<\/a>, Assistant Professor at Stanford, has been working toward this kind of biofuel production for many years.\u00a0 His University profile contains the following:<\/p>\n

\""Rusted"<\/a>

“Rusted” copper used as catalyst in Dr. Kanan’s production of ethanol<\/p><\/div>\n

\u201cThe ability to convert H2O, CO2 and N2 into fuels using renewable energy inputs could in principle provide a viable alternative to the current dominance of fossil fuels. This prospect faces great technical challenges, the foremost of which is the lack of efficient and robust electrocatalysts for the various multi-electron processes that fuel synthesis demands. We are working to address this deficiency for the two most challenging reactions: CO2 reduction and N2 reduction. Our efforts focus on developing new heterogeneous electrocatalysts and unveiling the electrochemical mechanisms by which these catalysts operate. Materials of particular interest include metal\/metal oxide composites and nanostructured metal surfaces. The ultimate goals of this research area are to develop catalyst design principles that are applicable to multiple materials and to provide viable candidate electrode materials for electrolytic devices.\u201d<\/p>\n

Kanan and fellow researcher, Stanford graduate student Christina Li, have published the results of their research in the April 9 advanced online edition of the journal Nature<\/i><\/a>. \u00a0Most ethanol production requires high-temperature fermentation facilities that convert corn, sugarcane and other plants into liquid fuel.\u00a0 These types of production techniqes are energy intensive and highly resource dependent.\u00a0 As the Stanford press release by Mark Shwartz explains, \u201cIn some parts of the United States, it takes more than 800 gallons of water to grow a bushel of corn, which, in turn, yields about 3 gallons of ethanol.\u201d<\/p>\n

A better approach would be to consume the lowest energy possible in the process \u2013 to avoid using more than the system produces; and to avoid using plants at all.\u00a0 Let them live to give off oxygen and take in CO2<\/sup>.<\/p>\n

Kanan and Li had to craft a special electrode material made from \u201coxide-derived copper,\u201d formed from copper oxide, as the name implies. Kanan explains the subtle distinctions involved.\u00a0 “Conventional copper electrodes consist of individual nanoparticles that just sit on top of each other.\u00a0 Oxide-derived copper, on the other hand, is made of copper nanocrystals that are all linked together in a continuous network with well-defined grain boundaries. The process of transforming copper oxide into metallic copper creates the network of nanocrystals.”<\/p>\n

\"text\"<\/a>

Scanning electron microscope (SEM) and transmission electron microscope images of oxide-derived copper catalysts used in Stanford experiments. \u00a0Temperature involved were cool, as were experiments<\/p><\/div>\n

Conventional cells produce oxygen and hydrogen gas when a voltage is applied across the electrodes.\u00a0 Kanan and Li\u2019s cell has two electrodes placed in water saturated with carbon monoxide gas and reducing that carbon monoxide to ethanol.<\/p>\n

Their cathode made of oxide-derived copper required only a small voltage to produce \u201cdramatic\u201d results.<\/p>\n

“The oxide-derived copper produced ethanol and acetate with 57 percent faradaic efficiency. That means 57 percent of the electric current went into producing these two compounds from carbon monoxide. We’re excited because this represents a more than 10-fold increase in efficiency over conventional copper catalysts. Our models suggest that the nanocrystalline network in the oxide-derived copper was critical for achieving these results.”<\/p>\n

The video below gives the background for Kanan\u2019s work and at about the 27 minute mark details directly the work outlined here.\u00a0 The payoff in terms of what it would take to commercialize this and capture vast quantities of CO2 are a bit daunting, but as the scientist points out, a smaller effort than building the numbers of cars we produce each year.\u00a0 One can only imagine the number of jobs this would create.<\/p>\n