We have dwelled, we are certain, to the point of weariness with many of our readers, on fact that Carbon Dioxide, rather than being a troublesome pollutant, is, instead, a valuable raw material resource that arises, in only a small way, compared to natural sources, from our use of coal.
In the course of it all, we have documented that, as far back as the 1960's, it was known among our Defense establishment that, as the Nobel Committee had even much earlier affirmed, Carbon Dioxide could be collected and converted, recycled, into liquid and gaseous hydrocarbons which could serve as raw materials for the production of gasoline and plastics.
More recently, our US Department of Energy has been developing the technology to use environmental, "renewable", energy to accomplish the transmutation of CO2 into useful hydrocarbons.
Much of the work, as we have documented to be true of that undertaken by Rich Diver, at Sandia National Laboratory, has been focused on developing the technology and equipment to harness solar, "light", energy to enable the recycling of CO2.
Herein, we find that our US DOE has engaged others to research such technology, as well. .
Under Contract Number DE-FG26-99FT40579, the University of Akron, OH, has been developing:
"CO2 Sequestration and Recycle by Photocatalysis with Visible Light
Final Report; Starting Date: 7-1-1999; End Date: 6-30-2000
Steven S. C. Chuang
Oct. 2001
DE-FG26-99FT40579
Steven S. C. Chuang
Oct. 2001
DE-FG26-99FT40579
Department of Chemical Engineering; The University of Akron; Akron, OH 44325-3906
ABSTRACT
Visible light-photocatalysis could provide a cost-effective route to recycle CO2 to useful
chemicals or fuels. Development of an effective catalyst for the photocatalytic synthesis requires
(i) the knowledge of the surface band gap and its relation to the surface structure, (ii) the reactivity of adsorbates and their reaction pathways, and (iii) the ability to manipulate the actives site for adsorption, surface reaction, and electron transfer. The objective of this research is to study the photo-catalytic activity of TiO 2-base catalyst. A series of TiO 2-supported metal catalysts were prepared for determining the activity and selectivity for the synthesis of methane and methanol. 0.5 wt% Cu/SrTiO 3 was found to be the most active and selective catalyst for methanol synthesis. The activity of the catalyst decreased in the order: Ti silsesquioxane > Cu/SrTiO 3 > Pt/TiO 2 > Cu/TiO2 > TiO2 > Rh/TiO2. To further increase the number of site for the reaction, we propose to prepare monolayer and multiplayer TiOx on high surface area mesoporous oxides. These catalysts will be used for in situ IR study in the Phase II research project to determine the reactivity of adsorbates. Identification of active adsorbates and sites will allow incorporation of acid/basic sites to alter the nature of CO2 and H2O adsorbates and with Pt/Cu sites to direct reaction pathways of surface intermediates, enhancing the overall activity and selectivity for methanol and hydrocarbon synthesis. The overall goal of this research is to provide a greater predictive capability for the design of visible light-photosynthesis catalysts by a deeper understanding of the reaction kinetics and mechanism as well as by better control of the coordination/chemical environment of active sites.
CONCLUSION
The long-term goal of our research has been to develop a fundamental understanding of the reactivity of adsorbates and their relationships with the nature of sites, reaction kinetics, and deactivation resistance. 0.5 wt% Cu/SrTiO 3 was found to be the most active and selective catalyst for methanol synthesis. The activity of the catalyst decreased in the order: Ti silsesquioxane > Cu/SrTiO 3 > Pt/TiO 2 > Cu/TiO2 > TiO2 > Rh/TiO2. To further increase the number of site for the reaction, we propose to prepare monolayer and multiplayer TiO x on high surface area mesoporous oxides. Preparation of supported monolayer oxides and sulfide catalysts with metal sites and acid/base functionality as well as investigation of their structures and catalytic properties constitutes an important and innovative element of next phase study. The unique coordination of these monolayer sites and their chemical environments promises to open opportunity for development of new types of photocatalysis for methanol and hydrocarbon synthesis from CO2 and H2O."
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We'll close here with a few comments, and a question. Following is the full and rather impressive list of references. We include it without editing just, once again, to illustrate how much information might really be "out there", which would, as with the technologies for converting coal into liquid fuel and chemicals, allow us to overcome the foreign petroleum tyranny through the full, and fully-informed, use of our own, abundant, domestic resources.
Finally, though, we quote, with some creative editing, the concluding sentence of the Abstract: there is technology which "promises ... opportunity for development of new types of methanol and hydrocarbon synthesis from CO2 and H2O".
That conclusion was submitted to our USDOE nearly nine years ago. Has anything been built on that foundation in what has been the better part of a decade since?
Opportunity has knocked. It's still waiting for someone to open the door.
REFERENCES
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2. M. Anpo, in “Surface Photochemistry”, John Wiley and Sons, New York 1995.
3. C. Kutal, N. Sepone, in “Photosensitive Metal-Organic System”, Advances in Chemistry
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