H2 Production by Methane Oxy-Reforming: Effect of Catalyst Pretreatment on the Properties and Activity of Rh-Ce0.5Zr0.5O2 Synthetized by Microemulsion

Abstract

Green hydrogen introduction in hard-to-abate processes is held back by the cost of substituting steam reforming plants with electrolyzers. However, green hydrogen can be integrated in properly modified reforming processes. The process proposed here involves the substitution of steam reforming with oxy-reforming, which is the coupling of the former with catalytic partial oxidation (CPO), exploiting the pure oxygen coproduced during electrolysis to feed CPO, which allows for better heat exchange thanks to its exothermic nature. With the aim of developing tailored catalysts for the oxy-reforming process, Ce0.5Zr0.5O2 was synthetized by microemulsion and impregnated with Rh. The Ce-based supports were calcined at different temperatures (750 and 900 °C) and the catalysts were reduced at 750 °C or 500 °C. Tuning the calcination temperature allowed for an increase in the support surface area, resulting in well-dispersed Rh species that provided a high reducibility for both the metal active phase and the Ce-based support. This allowed for an increase in methane conversion under different conditions of contact time and pressure and the outperformance of the other catalysts. The higher activity was related to well-dispersed Rh species interacting with the support that provided a high concentration of surface OH* on the Ce-based support and increased methane dissociation. This anticipated the occurrence and the extent of steam reforming over the catalytic bed, producing a smoother thermal profile.

Molecular Ruthenium Cyclopentadienone Bifunctional Catalysts for the Conversion of Sugar Platforms to Hydrogen

“…Another way in which carbon dioxide could be formed is the water gas shift reaction (Eq. (3)) occurring over carbon monoxide that can be formed in reforming reactions [78,79] . However, according to the reaction mechanism proposed here and validated by NMR analysis, glucose decomposition over Shvo does not involve the decarbonylation of the substrate to give CO, while formic acid decomposition is responsible for direct CO 2 production.…”

“…( 3)) occurring over carbon monoxide that can be formed in reforming reactions. [78,79] However, according to the reaction mechanism proposed here and validated by NMR analysis, glucose decomposition over Shvo does not involve the decarbonylation of the substrate to give CO, while formic acid decomposition is responsible for direct CO 2 production. With the aim of detecting arabinose reforming products, APR was directly conducted using arabinose as a substrate in a J-Young's tap NMR tube for an in situ monitoring (DMSO d 6 -D 2 O 1 : 1 solvent mixture, 2 mol % 1, 4 h, 150 °C).…”

An innovative catalytic pathway for the synthesis of acyl furans: the cross-ketonization of methyl 2-furoate with carboxylic acids

“…Then, after several hours on stream the conversion dropped down, roughly matching the sum of yields. This trend, unseen over ZrO 2 , was attributed to the wellknown redox activity CeO 2 and Ce/Zr/O, [50][51][52] which fostered the decomposition of 2-MF into gaseous products such as propylene and butylene, which were identified by means of GC-MS but could not be quantified with the online GC-TCD system used. The H 2 -TPR characterization of the 3 catalysts shown in Fig.…”

Microemulsions of Nonionic Surfactant with Water and Various Homologous Esters: Preparation, Phase Transitions, Physical Property Measurements, and Application for Extraction of Tricyclic Antidepressant Drugs from Aqueous Media

“…Nanomaterials 2023, 13, x FOR PEER REVIEW 2 of 32 [13][14][15], alternative fuels [16,17], catalysis [18][19][20], templated synthesis of nanoparticles [21][22][23][24][25][26], and environmental remediation [27][28][29][30][31].…”

“…Microemulsions have emerged over the past decades as a major research topic in colloid science. This is primarily due to their multiple areas of application, spanning fields like cosmetics [ 1 , 2 , 3 ], pharmaceuticals [ 4 , 5 , 6 , 7 ], agriculture [ 8 , 9 ], food [ 10 , 11 , 12 ], oil recovery [ 13 , 14 , 15 ], alternative fuels [ 16 , 17 ], catalysis [ 18 , 19 , 20 ], templated synthesis of nanoparticles [ 21 , 22 , 23 , 24 , 25 , 26 ], and environmental remediation [ 27 , 28 , 29 , 30 , 31 ].…”