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The reverse water-gas shift (RWGS) reaction offers a sustainable approach for CO2 utilization, yielding CO for vital catalytic processes. This study compares the catalytic performance of exsolved Cu- and Ni-encapsulated silicalite-1 (S-1) catalysts against those prepared by impregnation methods. Exsolved catalysts, characterized by confined metal nanoparticles and distinct surface chemistry, exhibited higher CO selectivity and lower activation energies of CO formation than their impregnated counterparts. Surface and structural analyses revealed that the exsolution process enhanced RWGS activity, driven by altered metal-support interactions and unique adsorption behaviors, offering insights for improving the efficiency of RWGS catalysis. [ABSTRACT FROM AUTHOR]

Catalytic thermochemical conversion offers a sustainable method to upgrade oil‐based feedstocks into highly valuable biofuel, aligning with the modern biorefinery concept. Herein, a series of IrRe/SAPO‐11 catalysts with different Ir to Re molar ratios compared to reference Ir/SAPO‐11 and Re/SAPO‐11 catalysts was prepared using a wetness impregnation method. These catalysts were used for the direct production of sustainable aviation fuels (SAFs) via efficient hydrodeoxygenation and hydroisomerization of triglycerides. The catalyst screening confirmed that the optimum IrRe/SAPO‐11 catalyst, with an equivalent Ir to Re molar ratio, exhibited the highest hydrodeoxygenation activity under milder operation conditions than the conditions used in previous studies. Increasing the reaction temperature up to 330 °C enhanced the formation of iso‐alkanes in the liquid product, achieving a freezing point of −31.4 °C without additional cold flow improvers. Furthermore, a long‐term stability experiment demonstrated that the developed Ir−Re system exhibited exceptional performance over 150 h. This excellent catalytic activity and stability of the bifunctional IrRe/SAPO‐11 catalyst was owing to its suitable interface between metallic and oxide sites, mixed mesoporous structures, reduced catalyst size, and increased Lewis acid ratio, as confirmed by our comprehensive characterizations. [ABSTRACT FROM AUTHOR]

Methane is a highly potent greenhouse gas which contributes to the pressing global warming issue in the world. Methanol derived from methane was one of the solutions to prevent the escalating greenhouse effect. However, the process was energy intensive and hence pinch technology was used to optimize the heat efficiency in the process. This study aims to determine the optimum ΔTmin indicated with lowest total cost via HINT software. Results shown that the optimum heat exchanger configuration was obtained by network with ΔTmin 10 K, with minimum operating and capital cost of $2,729,590/year and $579,129,590/year respectively.

The main aim of this work was to develop a heterogeneous Fe2O3/CaO2 bifunctional catalyst prepared from iron sand and 3 different CaO2 sources (CaCO3, Ca (OH)2, and limestone) using wet impregnation and calcination methods for biodiesel production. The effects of different CaO2 sources and Fe/Ca ratio in the catalyst were investigated to provide insight into the catalyst character and biodiesel yield. X-ray diffraction, X-ray fluorescence, and scanning electron microscopy analyses were used to characterize the catalyst. CaCO3 was concluded as the best CaO2 source, while the best Fe/Ca configuration was found to be 1:4, giving the highest biodiesel yield (97.0401%) with no diglycerides. Greater addition of Fe loading would result in an amorphous structure, and all catalysts were relatively crystalline. Fe was concluded to favor the esterification reaction and biodiesel formation, while CaO2 was seen to favor the transesterification reaction and fatty acid methyl ester (FAME) formation. The catalyst mechanism was also established in this study, where esterification of free fatty acid (FFA) and glycerol took place on the acid site to produce diglyceride and transesterification of triglyceride by methanol occurred on the basic site. [ABSTRACT FROM AUTHOR]

The study aimed to optimize a waste-cooking oil-based biodiesel production process using α-Fe2O3/Hydroxyapatite (HAP) catalyst from natural iron sand and phosphate rocks. The parameters investigated in this study were reaction temperature, methanol:WCO molar ratio, and catalyst weight. Response surface methodology (RSM) with central composite design (CCD) was used to design the experiment, and a model in the form of a quadratic equation was later generated based on the investigated parameters and the observed biodiesel yield response. The model was subjected to ANOVA analysis to determine its validity and the influence of the investigated parameters on the observed response. The results showed that the catalyst weight was the only parameter significantly influencing the biodiesel yield, although the reaction temperature was concluded to be borderline significant. The optimal reaction condition suggested was 70°C reaction temperature with 3.68%w/w catalyst weight and 10.47 mol/mol methanol:WCO molar ratio to achieve 93.96% biodiesel yield. [ABSTRACT FROM AUTHOR]

Catalytic thermochemical conversion offers a sustainable method to upgrade oil-based feedstocks into highly valuable biofuel, aligning with the modern biorefinery concept. Herein, a series of IrRe/SAPO-11 catalysts with different Ir to Re molar ratios compared to reference Ir/SAPO-11 and Re/SAPO-11 catalysts was prepared using a wetness impregnation method. These catalysts were used for the direct production of sustainable aviation fuels (SAFs) via efficient hydrodeoxygenation and hydroisomerization of triglycerides. The catalyst screening confirmed that the optimum IrRe/SAPO-11 catalyst, with an equivalent Ir to Re molar ratio, exhibited the highest hydrodeoxygenation activity under milder operation conditions than the conditions used in previous studies. Increasing the reaction temperature up to 330 °C enhanced the formation of iso-alkanes in the liquid product, achieving a freezing point of -31.4 °C without additional cold flow improvers. Furthermore, a long-term stability experiment demonstrated that the developed Ir-Re system exhibited exceptional performance over 150 h. This excellent catalytic activity and stability of the bifunctional IrRe/SAPO-11 catalyst was owing to its suitable interface between metallic and oxide sites, mixed mesoporous structures, reduced catalyst size, and increased Lewis acid ratio, as confirmed by our comprehensive characterizations., (© 2024 The Authors. ChemPlusChem published by Wiley-VCH GmbH.)