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In this study, the potential of petroleum sludge (PS) for hydrogen production via the gasification process was evaluated. For this purpose, nickel (Ni)-loaded ZSM-5 and γ-Al 2 O 3 (Ni-ZS and Ni-Al) catalysts were prepared and employed for PS gasification in air condition. The effects of different supports, Ni loading content, and reaction temperatures on the production of hydrogen-rich syngas along with the stability and reusability of the best catalyst were investigated. Applying 5%Ni-ZS obtained more gas yield (68.09 wt%) and hydrogen selectivity (25.04 vol%) compared to those obtained by 5%Ni-Al mostly owing to weak metal-support interactions which led to the dominance of well-dispersed metallic Ni. At various Ni loading percentages, 10%Ni-ZS showed the highest catalytic efficiency, which increased both gas yield (70.92 wt%) and hydrogen selectivity (30.74 vol%). However, excessive Ni content (especially 20%) significantly reduced the gas yield and hydrogen selectivity because of limited accessibility of support's active sites, poor dispersion of Ni, and inappropriate acidity. Increasing the temperature promoted the gas yield and produced hydrogen, where the highest gas yield (73.18 wt%) and hydrogen selectivity (33.15 vol%) were obtained at 850 °C due to the endothermic nature of gasification reactions. The 10%Ni-ZS catalyst showed proper stability during three consecutive experiments at 850 °C. The spent catalyst was successfully regenerated without a significant reduction in activity or selectivity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Steam gasification of microalgae upon perovskite oxide-supported nickel (Ni) catalysts was carried out for H 2 -rich gas production. Ni-perovskite oxide catalysts with partial substitution of B in perovskite structures (Ni/CaZrO 3 , Ni/Ca(Zr 0.8 Ti 0.2 )O 3 , and Ni/Ca(Zr 0.6 Ti 0.4 )O 3 ) were synthesized and compared with those of the Ni/Al 2 O 3 catalyst. The perovskite oxide supports improved Ni dispersion by reducing the particle size and strengthening the Ni-support interaction. Higher gas yields and H 2 selectivity were obtained using Ni-perovskite oxide catalysts rather than Ni/Al 2 O 3 . In particular, Ni/Ca(Zr 0.8 Ti 0.2 )O 3 showed the highest activity and selectivity for H 2 production because of the synergetic effect of metallic Ni and elements present in the perovskite structures caused by high catalytic activity coupled with enhanced oxygen mobility. Moreover, increasing the temperature promoted the yield of gas and H 2 content. Overall, considering the outstanding advantages of perovskite oxides as supports for Ni catalysts is a promising prospect for H 2 production via gasification technology., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Abstract: Nickel-alumina/silica thin film materials for the use in solar thermal absorbers have been investigated using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Elastic Recoil Detection Analysis (ERDA). The TEM images revealed that all layers have a very small thickness variation and that the layers are completely homogenous. High resolution images showed 5–10nm (poly) crystalline nickel nano-particles. ERDA showed that both the silica and alumina compositions contain more oxygen than 2:1 and 3:2 respectively. SEM showed the surface morphology and characteristics of the top silica anti-reflection layer. Hybrid-silica has showed to generate a smoother surface with less cracking compared to pure silica. The final curing temperature revealed to be of importance for the formation of cracks and the surface morphology. [Copyright &y& Elsevier]

Abstract: Thin film materials for the use in solar thermal absorbers have been investigated using time-of-flight energy elastic recoil detection analysis (ERDA). The ERDA measurements proved to be very efficient in detecting the elemental depth composition of a selective solar absorber. The three-layer absorber is composed of an 80% nickel–20% alumina film at the base, a 40% nickel–60% alumina layer in the middle and finally an AR film of silica or hybrid-silica film at the top. The difference between solution volume percent and actual volume percent could be investigated when studying individual nickel–alumina films with varying ratios coated on glass substrates. The result showed that there was a maximum difference of 3% between the calculated solution volume percent and the actual volume percentages in the solid films. The ERDA measurements also indicate that about 15% of the nickel found in the nickel–alumina composite films is bound in the form of NiO. [Copyright &y& Elsevier]