Methanation and photo-methanation of carbon dioxide at room temperature and atmospheric pressure

Thampi, K. Ravindranathan; Kiwi, J.; Grätzel, Michaël

doi:10.1038/327506a0

Cited by 367 publications

(207 citation statements)

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“…Noble metals including Pt, Ag, Au, Pd, Ni, Rh and Cu have been reported to be very effective at enhancing photocatalysis by TiO 2 [87][88][89][90][91][92]. Because the Fermi levels of these noble metals are lower than that of TiO 2 , photoexcited electrons can be transferred from the conduction band of TiO 2 to metal particles deposited on the surface of TiO 2 , while photogenerated holes in the valence band remain on TiO 2 .…”

Section: Addition Of Noble Metalsmentioning

confidence: 99%

“…Papp et al [88] found that the addition of palladium to TiO 2 powder by either photodecomposition or thermal decomposition increased its photocatalytic activity towards the degradation of 1,4-dichlorobenzene. Thampi et al [89] reported that Rh/TiO 2 samples exhibited a high activity for CO 2 photoreduction using hydrogen to selectively produce CH 4 . Adachi et al [90] reported CO 2 reduction using copper-doped TiO 2 powder at ambient temperature.…”

Section: Addition Of Noble Metalsmentioning

confidence: 99%

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A review of TiO2 nanoparticles

2011

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Climate change and the consumption of non-renewable resources are considered as the greatest problems facing humankind. Because of this, photocatalysis research has been rapidly expanding. TiO 2 nanoparticles have been extensively investigated for photocatalytic applications including the decomposition of organic compounds and production of H 2 as a fuel using solar energy. This article reviews the structure and electronic properties of TiO 2 , compares TiO 2 with other common semiconductors used for photocatalytic applications and clarifies the advantages of using TiO 2 nanoparticles. TiO 2 is considered close to an ideal semiconductor for photocatalysis but possesses certain limitations such as poor absorption of visible radiation and rapid recombination of photogenerated electron/hole pairs. In this review article, various methods used to enhance the photocatalytic characteristics of TiO 2 including dye sensitization, doping, coupling and capping are discussed. Environmental and energy applications of TiO 2 , including photocatalytic treatment of wastewater, pesticide degradation and water splitting to produce hydrogen have been summarized. Historical backgroundThe growth of industry worldwide has tremendously increased the generation and accumulation of waste byproducts. In general, the production of useful products has been focused on and the generation of waste byproducts has been largely ignored. This has caused severe environmental problems that have become a major concern. Researchers all over the world have been working on various approaches to address this issue. Photoinduced processes have been studied and various applications have been developed. One important technique for removing industrial waste is the use of light energy (electromagnetic radiation) and particles sensitive to this energy to mineralize waste which aids in its removal from solution. Titanium dioxide (TiO 2 ) is considered very close to an ideal semiconductor for photocatalysis because of its high stability, low cost and safety toward both humans and the environment.*Corresponding author (email: shipra.mital@gmail.com)In 1964, Kato et al.[1] published their work on the photocatalytic oxidation of tetralin (1,2,3,4-tetrahydronaphthalene) by a TiO 2 suspension, which was followed by McLintock et al. [2] investigating the photocatalytic oxidation of ethylene and propylene in the presence of oxygen adsorbed on TiO 2 . However, the most important discovery that extensively promoted the field of photocatalysis was the "Honda-Fujishima Effect" first described by Fujishima and Honda in 1972 [3]. This well-known chemical phenomenon involves electrolysis of water, which is related to photocatalysis. Photoirradiation of a TiO 2 (rutile) single crystal electrode immersed in an aqueous electrolyte solution induced the evolution of oxygen from the TiO 2 electrode and the evolution of hydrogen from a platinum counterelectrode when an anodic bias was applied to the TiO 2 working electrode. In 1977, Frank and Bard [4] examined the reduction of ...

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Section: Addition Of Noble Metalsmentioning

confidence: 99%

Section: Addition Of Noble Metalsmentioning

confidence: 99%

A review of TiO2 nanoparticles

2011

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“…Its use for the production of chemicals is doubly beneficial, since in addition to its availability, it would represent a decrease in the carbon footprint for the manufacturing of the particular chemical. Catalytic processes are crucial for improving efficiency and conversion in the use of CO 2 for the manufacture of a wide range of substances, including methanol [1][2][3][4], carboxylic acids [1,4], polycarbonates [1,4,5], polylactones [1,6] or hydrocarbons [1,4,7,8]. As a particularly important matter, the catalytic production of hydrocarbon fuels from CO 2 constitutes a highly desirable strategy for the potential of closing the carbon cycle in future energy schemes.…”

Section: Introductionmentioning

confidence: 99%

Copper-doped titania photocatalysts for simultaneous reduction of CO2 and production of H2 from aqueous sulfide

Gonell

Puga

Julián‐López

et al. 2016

Applied Catalysis B: Environmental

108

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Copper-doped titanium dioxide materials with anatase phase (Cu-TiO 2 , atomic Cu contents ranging from 0 to 3% relative to the sum of Cu and Ti), and particle sizes of 12-15 nm, were synthesised by a solvo-thermal method using ethanol as the solvent and small amounts of water to promote the hydrolysis-condensation processes. Diffuse reflectance UV-vis spectroscopy show that the edges of absorption of the titania materials are somewhat shifted to higher wavelengths due to the presence of Cu. X-Ray Photoelectron Spectroscopy (XPS) indicate that Cu(II) is predominant. Photocatalytic CO 2 reduction experiments were performed in aqueous Cu-TiO 2 suspensions under UV-rich light and in the presence of different solutes. Sulfide was found to promote the efficient production of H 2 from water and formic acid from CO 2 . The effect of the Cu content on the photoactivity of Cu-TiO 2 was also studied, showing that copper plays a role on the photocatalytic reduction of CO 2 . IntroductionCarbon dioxide is an inexpensive and widely available feedstock. Its use for the production of chemicals is doubly beneficial, since in addition to its availability, it would represent a decrease in the carbon footprint for the manufacturing of the particular chemical. Other researchers have reported lower but noticeable methanol yields using similarly prepared photocatalysts and Hg lamp irradiation (10-23 µmol g cat −1 h −1 ) [19,20]. In gas-phase reactions, the formation of methanol was also reported, but in considerably lower yields (2 nmol g cat −1 h −1 ), being methane the major product formed by Cu/TiO 2 photocatalysis [21]. In contrast, similar materials were found to promote the formation of several hydrocarbons including methane, ethane and ethylene in conjunction with larger amounts of H 2 [22], whereas CO and methane were major products found in a more recent study [23]. A significant degree of discrepancy regarding the identity of the reaction products (in addition to their selectivities and yields) is apparent by considering the aforementioned literature data, although this could be in part due to the different synthetic procedures used for the preparation of the photocatalysts and to the varied irradiation conditions used.Despite the notable progress in this field of research, there is no clear trend which may allow to conclude on the actual mechanistic route and to gain knowledge on the role of copper on the reaction. Thorough kinetic and in situ spectroscopic studies would provide valuable information on the reaction at the surface of the photocatalyst and may guide future design of more active copper-titania materials. An important issue to focus on is the possible back-reactions of the reduction products on the photocatalyst. For example, it was observed that methanol and formaldehyde, initially formed by a photocatalytic process using Cu(0) powder and TiO 2 , were 3 rapidly consumed by in situ formed Cu/TiO 2 [24]. The simultaneous occurrence of CO 2 reduction and decomposition of the products should result in stat...

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“…Various physiochemical methods have been reported for the fixation of CO 2 gas, such as carbonates, geological or ocean storage or afforestation [1][2][3][4]. However, these approaches have severe drawbacks in terms of economic factors, safety, efficiency, and reliability of their immediate application.…”

Section: Introductionmentioning

confidence: 99%

Titanium dioxide supported ruthenium nanoparticles for carbon sequestration reaction

Upadhyay¹,

Srivastava²

2016

Nanosystems: Phys. Chem. Math.

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Ru metal doped TiO 2 nanoparticles were synthesized using a sol gel method with and without ionic liquid. Ru metal is well dispersed while utilizing ionic liquid as reaction medium for catalyst synthesis with respect to Ru-TiO 2 catalyst. A TEM image for Ru-TiO 2 -IL catalyst reveals, stable, well dispersed and agglomeration free Ru metal doped TiO 2 nanoparticles. CO 2 Hydrogenation reaction on task specific ionic liquid medium, offered the formic acid in high TON/TOF value with added advantage of 5 times catalyst recycling.

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Methanation and photo-methanation of carbon dioxide at room temperature and atmospheric pressure

Cited by 367 publications

References 0 publications

A review of TiO2 nanoparticles

A review of TiO2 nanoparticles

Copper-doped titania photocatalysts for simultaneous reduction of CO2 and production of H2 from aqueous sulfide

Titanium dioxide supported ruthenium nanoparticles for carbon sequestration reaction

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