skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: CO2 Sequestration and Recycle by Photosynthesis

Abstract

Hydrocarbon oxygenate synthesis from photocatalytic reactions of CO{sub 2} and H{sub 2}O over various catalysts is a very attractive process. However, the formation rate of the hydrocarbons and oxygenates is significantly lower than conventional catalysis. One possible reason for the low rate of product formation is the presence of oxidation sites which reoxidize the products back to CO{sub 2} and H{sub 2}O. For further improvement of catalytic activity for the reduction process, it is essential to understand the oxidation reaction process. We have studied photocatalytic oxidation of methylene blue and found the oxidation rate is significantly higher than the reduction rate.

Authors:
Publication Date:
Research Org.:
University of Akron
Sponsoring Org.:
USDOE
OSTI Identifier:
883710
DOE Contract Number:
FG26-01NT41294
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 01 COAL, LIGNITE, AND PEAT; CARBON SEQUESTRATION; CARBON DIOXIDE; HYDROCARBONS; METHYLENE BLUE; OXIDATION; PROGRESS REPORT; REDOX REACTIONS; PHOTOCATALYSIS

Citation Formats

Steven S.C. Chuang. CO2 Sequestration and Recycle by Photosynthesis. United States: N. p., 2006. Web. doi:10.2172/883710.
Steven S.C. Chuang. CO2 Sequestration and Recycle by Photosynthesis. United States. doi:10.2172/883710.
Steven S.C. Chuang. Sun . "CO2 Sequestration and Recycle by Photosynthesis". United States. doi:10.2172/883710. https://www.osti.gov/servlets/purl/883710.
@article{osti_883710,
title = {CO2 Sequestration and Recycle by Photosynthesis},
author = {Steven S.C. Chuang},
abstractNote = {Hydrocarbon oxygenate synthesis from photocatalytic reactions of CO{sub 2} and H{sub 2}O over various catalysts is a very attractive process. However, the formation rate of the hydrocarbons and oxygenates is significantly lower than conventional catalysis. One possible reason for the low rate of product formation is the presence of oxidation sites which reoxidize the products back to CO{sub 2} and H{sub 2}O. For further improvement of catalytic activity for the reduction process, it is essential to understand the oxidation reaction process. We have studied photocatalytic oxidation of methylene blue and found the oxidation rate is significantly higher than the reduction rate.},
doi = {10.2172/883710},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Feb 12 00:00:00 EST 2006},
month = {Sun Feb 12 00:00:00 EST 2006}
}

Technical Report:

Save / Share:
  • Hydrocarbon synthesis from photocatalytic reactions of CO{sub 2} and H{sub 2}O over various catalysts has been studied by UV-visible light. The quantum efficiencies suggest that Pd/TiO{sub 2} sol gel exhibits the highest activity for hydrocarbon synthesis from photocatalytic reactions. The in situ IR could successfully monitor the adsorbed hydrocarbon species. The UV-visible, IR spectroscopy and XRD techniques were used to characterize the catalysts to obtain the information of properties of the process and catalyst before/after reaction. The UV-visible spectroscopy provides the information about the surface band gap energy of each catalyst. In situ UV-visible studies reveals that TiO{sub 2}-supported catalystsmore » require the higher energy (i.e. shorter wavelength) to pass through the water-thin film deposited on the surface to activate the photocatalytic reaction. XRD data show there is changes in the crystal structure of TiO{sub 2} sol gel from photon energy during photo reaction. The information from this study can lead to a better understanding of the nature of the catalysts and photoreaction processes, which might provide the information to develop better catalysts and reaction process for the hydrocarbon synthesis from photocatalytic reactions of CO{sub 2} and H{sub 2}O.« less
  • Visible light-photocatalysis could provide a cost-effective route to recycle CO{sub 2} to useful chemicals or fuels. Research is planned to study the reactivity of adsorbates, their role in the photosynthesis reaction, and their relation to the nature of surface sites during photosynthesis of methanol and hydrocarbons from CO{sub 2}/H{sub 2}O over four types of MCM-41/Al{sub 2}O{sub 3}-supported TiO{sub 2} and CdS catalysts: (1) ion-exchanged metal cations, (2) highly dispersed cations, (3) monolayer sites, and (4) modified monolayer catalysts. TiO{sub 2} was selected since it has exhibited higher activity than other oxide catalysts; CdS was selected for its photocatalytic activity inmore » the visible light region. Al{sub 2}O{sub 3} provides excellent hydrothermal stability. MCM-41 offers high surface area (more than 800 m{sup 2}/g), providing a platform for preparing and depositing a large number of active sites per gram catalyst. The unique structure of these ion exchange cations, highly dispersed cations, and monolayer sites provides an opportunity to tailor their chemical/coordination environments for enhancing visible-light photocatalytic activity and deactivation resistance. The year one research tasks include (1) setting up experimental system, (2) preparing ion-exchanged metal cations, highly dispersed cations, monolayer sites of TiO{sub 2} and CdS, and (3) determination of the dependence of methanol activity/selectivity on the catalyst preparation techniques and their relation to adsorbate reactivity. During the first quarter, we have purchased a Gas Chromatography and all the necessary components for building 3 reactor systems, set up the light source apparatus, and calibrated the light intensity. In addition, monolayer TiO{sub 2}/MCM-41 and TiO{sub 2}/Al{sub 2}O{sub 3} catalyst were prepared. TiO{sub 2}/Al{sub 2}O{sub 3} was found to exhibit high activity for methanol synthesis. Repeated runs was planned to insure the reproducibility of the data.« less
  • Visible light-photocatalysis could provide a cost-effective route to recycle CO2 to useful chemicals or fuels. Research is planned to study the reactivity of adsorbates, their role in the photosynthesis reaction, and their relation to the nature of surface sites during photosynthesis of methanol and hydrocarbons from CO{sub 2}/H{sub 2}O. The year two research focus catalyst screening and IR studies. Key research results show Pd/TiO2 exhibits the highest activity for hydrocarbon synthesis from photocatalytic reactions. The in situ IR could successfully monitor the adsorbate hydrocarbon species on Cu/TiO2. Year III research will focus on developing a better understanding of the keymore » factors which control the catalyst activity.« less
  • Hydrocarbon synthesis from photocatalytic reactions of CO{sub 2} and H{sub 2}O over various catalysts has been studied by UV-visible light. The quantum efficiencies suggest that Pd/TiO{sub 2} sol gel exhibits the highest activity for hydrocarbon synthesis from photocatalytic reactions. The in situ IR was able to monitor the adsorbed hydrocarbon species. The UV-visible, IR spectroscopy and XRD techniques were used to characterize the catalysts to obtain the information of properties of the process and catalyst before/after reaction. The UV-visible spectroscopy provides the information about the surface band gap energy of each catalyst. In situ UV-visible studies reveals that TiO{sub 2}-supportedmore » catalysts require the higher energy (i.e. shorter wavelength) to pass through the water-thin film deposited on the surface to activate the photocatalytic reaction. XRD data show there is changes in the crystal structure of TiO{sub 2} sol gel from photon energy during photo reaction. Studies on photocatalytic oxidation of methylene blue show that the photocatalytic oxidation rate is significantly higher than the photocatalytic reduction rate on TiO{sub 2} based catalysts. The information from this study can lead to a better understanding of the nature of the catalysts and photoreaction processes, which might provide the information to develop better catalysts and reaction process for the hydrocarbon synthesis from photocatalytic reactions of CO{sub 2} and H{sub 2}O.« less
  • Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarilymore » at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report is the summary first year report covering the reporting period 1 October 2000 to 30 September 2001 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work conducted during the previous reporting period, PSI initiated work on the component optimization work. Aquasearch continued their effort on selection of microalgae suitable for CO{sub 2} sequestration. University of Hawaii initiated effort on system optimization of the CO{sub 2} sequestration system.« less