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In this work, the influence of sulfated temperature on the selective catalytic reduction of NO by NH 3 over the sulfated CeO 2 was investigated. The NO conversion of the sulfated CeO 2 samples decreased with the increase of sulfated temperature. The fresh CeO 2 and the CeO 2 sulfated at different temperatures were characterized by X-ray diffraction (XRD), laser Raman spectroscopy (LRS), in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS), thermogravimetry and differential thermal analysis (TG-DTA), H 2 -temperature-programmed reduction (H 2 -TPR), and X-ray photoelectron spectroscopy (XPS). The obtained results indicate that the sulfation process was gradually deepened, and the existence states of sulfate species over CeO 2 were changed from surface sulfates to bulk-like sulfates and to bulk sulfates with raising the sulfated temperature. Meanwhile, the formed bulk-like and bulk sulfates were the main reason to result in the decrease of catalytic activity. In addition, the corresponding model was proposed to understand the interaction between sulfate species and CeO 2 influenced by sulfated temperature. Finally, bulk sulfates could be eliminated by H 2 O washing and the NO conversion of CeO 2 sulfated at 550 °C was recovered after H 2 O washing, which supports the proposed model.

The influence of CO-pretreatment on the properties of CuO–V2O5/γ-Al2O3 catalysts was investigated in the reduction of NO by CO.

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Quantum dot sensitized solar cells (QDSSCs) are attractive photovoltaic devices due to their simplicity and low material requirements. However, efforts to realize high efficiencies in QDSSCs have often been offset by complicated processes and expensive or toxic materials, significantly limiting their useful application. In this work, we have realized for the first time, high performance PbS QDSSCs based on TiO2 nanotube arrays (NTAs) via an in situ chemical deposition method controlled by a low electric field. An efficiency, η, of ~3.41% under full sun illumination has been achieved, which is 133.6% higher than the best result previously reported for a simple system without doping or co-sensitizing, and comparable to systems with additional chemicals. Furthermore, a high open-circuit voltage (0.64 V), short-circuit current (8.48 mA cm(-2)) and fill factor (0.63) have been achieved. A great increase in the quantity of the loaded quantum dots (QDs) in the NTAs was obtained from the in situ electric field assisted chemical bath deposition (EACBD) process, which was the most significant contributing factor with respect to the high JSC. The high VOC and FF have been attributed to a much shorter electron path, less structural and electronic defects, and lower recombination in the ordered TiO2 NTAs produced by oscillating anodic voltage. Besides, the optimal film thickness (~4 μm) based on the NTAs was much thinner than that of the control cell based on nanoporous film (~30.0 μm). This investigation can hopefully offer an effective way of realizing high performance QDSSCs and QD growth/installation in other nanostructures as well.

Solar-powered CO 2 conversion represents a promising green and sustainable approach for achieving a carbon-neutral economy. However, the rational design of a wide-spectrum sunlight-driven catalysis system for effective CO 2 reduction is an ongoing challenge. Herein, we report the preparation of a rhodium/aluminum (Rh/Al) nanoantenna photothermal catalyst that can utilize a broad range of sunlight (from ultraviolet to the near-infrared region) for highly efficient CO 2 methanation, achieving a high CH 4 selectivity of nearly 100% and an unprecedented CH 4 productivity of 550 mmol•g −1 •h −1 under concentrated simulated solar irradiation (11.3 W•cm −2 ). Detailed control experiment results verified that the CO 2 methanation process was facilitated by the localized surface plasmonic resonance and nanoantenna effects of the Rh/Al nanostructure under light irradiation. In operando temperature-programmed Fourier transform infrared spectroscopy confirmed that CO 2 methanation on the Rh/Al nanoantenna catalyst was a multistep reaction with CO as a key intermediate. The design of a wide-spectrum solar-driven photothermal catalyst provides a feasible strategy for boosting CO 2 -to-fuel conversion.

The promotional effect of SnO2 in a Ce/TiO2 catalyst for NH3-SCR reaction.