Photocatalytic CO₂ conversion over Au/TiO₂ nanostructures for dynamic production of clean fuels in a monolith photoreactor

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• 作者：Beenish Tahir ; Muhammad Tahir…
• 关键词：CO2 conversion ; H2 reductant ; Au ; doped TiO2 ; Interband transition ; Monolithic support ; Continuous photoreactor
• 刊名：Clean Technologies and Environmental Policy
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：18
• 期：7
• 页码：2147-2160
• 全文大小：2,591 KB
• 刊物类别：Engineering
• 刊物主题：Industrial and Production Engineering
  Industrial Chemistry and Chemical Engineering
  Industrial Pollution Prevention
  Environmental Economics
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1618-9558
• 卷排序：18

文摘

Global economic development intensifies the consumption of fossil fuels which results in increase of carbon dioxide (CO₂) concentration in the atmosphere. The technologies for carbon capture and utilization to produce cleaner fuels are of great significance. However, phototechnology provides one perspective for economical CO₂ conversion to cleaner fuels. In this study, CO₂ conversion with H₂ to selective fuels over Au/TiO₂ nanostructures using environment friendly continuous monolith photoreactor has been investigated. Crystalline nanoparticles of anatase TiO₂ were obtained in the Au-doped TiO₂ samples. The Au deposited over TiO₂ in metal state produced plasmonic resonance. CO₂ was efficiently converted to CO as the main product over Au/TiO₂ with a maximum yield rate of 4144 µmol g-catal.−1 h−1, 345 fold-higher than using un-doped TiO₂ catalyst. The significantly enhanced photoactivity of Au/TiO₂ catalyst was due to hindered charges recombination rate and Au metallic-interband transition. The photon energy in the UV range was high enough to excite the d-band electronic transition in the Au to produce CO, CH₄, and C₂H₆. The quantum efficiency over Au/TiO₂ catalyst for CO was considerably improved in the continuous monolith photoreactor. At higher space velocity, the yield rates of CO gradually reduced, but the initial rates of hydrocarbon yields increased. The stability of the recycled Au/TiO₂ catalyst was sustained in cyclic runs. Thus, Au-doped TiO₂ supported over monolith channels is promising for enhanced CO₂ photoreduction to high energy products. This provides pathway that phototechnology to be explored further for cleaner and economical fuels production.