The Role of Strontium in CeNiO3 Nano-Crystalline Perovskites for Greenhouse Gas Mitigation to Produce Syngas

The transition metal-based catalysts for the elimination of greenhouse gases via methane reforming using carbon dioxide are directly or indirectly associated with their distinguishing characteristics such as well-dispersed metal nanoparticles, a higher number of reducible species, suitable metal–support interaction, and high specific surface area. This work presents the insight into catalytic performance as well as catalyst stability of CexSr1−xNiO3 (x = 0.6–1) nanocrystalline perovskites for the production of hydrogen via methane reforming using carbon dioxide. Strontium incorporation enhances specific surface area, the number of reducible species, and nickel dispersion. The catalytic performance results show that CeNiO3 demonstrated higher initial CH4 (54.3%) and CO2 (64.8%) conversions, which dropped down to 13.1 and 19.2% (CH4 conversions) and 26.3 and 32.5% (CO2 conversions) for Ce0.8Sr0.2NiO3 and Ce0.6Sr0.4NiO3, respectively. This drop in catalytic conversions post strontium addition is concomitant with strontium carbonate covering nickel active sites. Moreover, from the durability results, it is obvious that CeNiO3 exhibited deactivation, whereas no deactivation was observed for Ce0.8Sr0.2NiO3 and Ce0.6Sr0.4NiO3. Carbon deposition during the reaction is mainly responsible for catalyst deactivation, and this is further established by characterizing spent catalysts.

Engineering the geometric and electronic structure of Ru via Ru-TiO2 interaction for enhanced selective hydrogenation

Modulation of the metal-support interaction plays a key role in many important chemical reactions. Here, by adjusting the reduction method of the catalyst and introducing oxygen vacancies in TiO2 to...

Strong Metal-Support Interaction in Copper Hexacyanoferrate Nanocubes Decorated Functionalized Multiwall Carbon Nanotubes for Enhanced Bi-functional Oxygen Electrocatalytic Activity and Stability

Development of an efficient non-precious metal-based bi-functional oxygen electro-catalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for various electrochemical energy conversion and storage devices. Prussian...

An Investigation of Strontium Doped Erbium Oxide Nanoparticles for Enhanced Photocatalytic Degradation of Organic Pollutants in Aqueous Solution

A simple wet impregnation approach had been used to the successful preparation of different weight percentages of strontium/niobium doped Er2O3 nanoparticles. The X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), high resolution transmission electron microscope (HR-TEM), Fourier transformed infrared spectroscopy (FTIR), and UV-visible (UV) spectroscopy was used to analyze the samples as they were prepared. With Sr and Nb doping at Er2O3 nanoparticles, the XRD patterns intensity was shifted, and its positioning was also shifted as weight percentages of doped were increased. Similarly, the lattice d spacing values were also decreased. According to HR-TEM images, Er2O3 seems to have a two-dimensional hexagonal nanoplate-like structure as well as being a few nm in size. The photocatalytic activities of pristine and Sr/Nb doped samples were evaluated against the methyl orange (MO) and rhodamine B (Rh B) dyes under UV-visible light irradiation. Within seventy-five minutes of UV-Visible light irradiation, the five-weight percentage of Sr doped Er2O3 nanoparticles shows significantly enhanced photocatalytic degradation efficiency against Rh B dye. The synergistic effect of the strong metal-support interaction between the Sr and Er2O3 nanoparticles could be attributed to the improved photocatalytic activity of the prepared samples. The cyclic stability and radical trapping experiments were also investigated against the same reaction conditions.

Effect of the reductive treatment on the state and electrocatalytic behavior of Pt in catalysts supported on Ti0.8Mo0.2O2-C composite

Ti(1-x)MoxO2-carbon composites are promising new supports for Pt-based electrocatalysts in polymer electrolyte membrane fuel cells offering exciting catalytic properties and enhanced stability against electrocorrosion. Pt and the mixed oxide form a couple liable for strong metal-support interaction (SMSI) phenomenon, generally manifesting itself in decoration of the metal particles by ultrathin layers of the support material upon annealing under reductive conditions. The aim of this work is to evaluate the SMSI phenomenon as a potential strategy for tailoring the properties of the electrocatalyst. A 20 wt% Pt/50 wt% Ti0.8Mo0.2O2-50 wt% C electrocatalyst prepared on Black Pearls 2000 carbon functionalized with HNO3 and glucose was reduced at 250 °C in H2 in order to induce SMSI. The electrocatalytic properties and the stability of the reduced and the original catalysts were analyzed by cyclic voltammetry and COads stripping voltammetry. Structural investigations as well as X-ray photoelectron spectroscopy (XPS) measurements were performed in order to obtain information about the details of the interaction between the oxide and the Pt particles. The electrochemical experiments pointed out a small loss of the electrochemically active surface area of Pt in the reduced catalyst along with enhanced stability with respect to the original one, while structural studies suggested only a minimal decrease of the Pt dispersion. At the same time, hydrogen exposure experiments combined with XPS demonstrated the presence of Mo species directly adsorbed on the Pt surface. Thus, the properties of the reduced catalyst can be traced to decoration of the surface of Pt by Mo-containing species.