A high-purity gas-solid photoreactor for reliable and reproducible photocatalytic CO reduction measurements.

Reactions between a gas phase and a solid material are of high importance in the study of alternative ways for energy conversion utilizing otherwise useless carbon dioxide (CO). The photocatalytic CO reduction to hydrocarbon fuels like e.g.

Pivotal Role of Holes in Photocatalytic CO Reduction on TiO.

Evidence is provided that in a gas-solid photocatalytic reaction the removal of photogenerated holes from a titania (TiO ) photocatalyst is always detrimental for photocatalytic CO reduction. The coupling of the reaction to a sacrificial oxidation reaction hinders or entirely prohibits the formation of CH as a reduction product. This agrees with earlier work in which the detrimental effect of oxygen-evolving cocatalysts was demonstrated.

Judging the feasibility of TiO as photocatalyst for chemical energy conversion by quantitative reactivity determinants.

In this study we assess the general applicability of the widely used P25-TiO in gas-phase photocatalytic CO reduction based on experimentally determined reactivity descriptors from classical heterogeneous catalysis (productivity) and photochemistry (apparent quantum yield/AQY). A comparison of the results with reports on the use of P25 for thermodynamically more feasible reactions and our own previous studies on P25-TiO as photocatalyst imply that the catalytic functionality of this material, rather than its properties as photoabsorber, limits its applicability in the heterogeneous photocatalytic CO reduction in the gas phase. The AQY of IrO/TiO in overall water splitting in a similar high-purity gas-solid process was four times as high, but still far from commercial viability.

The fate of O in photocatalytic CO reduction on TiO under conditions of highest purity.

Although the photocatalytic reduction of CO2 to CH4 by using H2O as the oxidant presupposes the formation of O2, it is often not included in the product analysis of most of the studies dealing with photocatalytic CO2 reduction or it is reported to be not formed at all. The present study aims to clarify the absence of O2 in the photocatalytic gas phase CO2 reduction on TiO2. By modifying P25-TiO2 with IrOx co-catalysts it was possible to observe photocatalytic water splitting, i.

Development of a tubular continuous flow reactor for the investigation of improved gas-solid interaction in photocatalytic CO reduction on TiO.

A self-made, low-cost tubular reactor for the gas-phase photocatalytic CO2 reduction was developed. The resulting flow conditions cause an intensive interaction between the reactants in the gas-phase and the fixed bed photocatalyst. This approach is used to test the scalability of tubular reactors for the photocatalytic CO2 reduction.

Au@TiO Core-Shell Composites for the Photocatalytic Reduction of CO.

Au/TiO catalysts in different geometrical arrangements were designed to explore the role of morphology and structural properties for the photocatalytic reduction of CO with H O in the gas-phase. The most active sample was a Au@TiO core-shell catalyst with additional Au nanoparticles (NPs) deposited on the outer surface of the TiO shell. CH and CO are the primary carbon-containing products.

Identification and exclusion of intermediates of photocatalytic CO₂ reduction on TiO₂ under conditions of highest purity.

Using a high-purity gas phase photoreactor and highly sensitive trace gas analysis, new insights into the mechanism of photocatalytic CO2 reduction on TiO2 P25 have been obtained. The reactor design and sample pretreatment excludes product formation from intermediates. Apart from CO2, the only other reactant offered to the catalyst is water.