Hydrogen production through methanol reforming processes has been stimulated over the years due to increasing interest in fuel cell technology and clean energy production. Among different types of methanol reforming, the steam reforming of methanol has attracted great interest as reformate gas stream where high concentration of hydrogen is produced with a negligible amount of carbon monoxide. In this review, recent progress of the main reforming processes of methanol towards hydrogen production is summarized. Different catalytic systems are reviewed for the steam reforming of methanol: mainly copper- and group 8–10-based catalysts, highlighting the catalytic key properties, while the promoting effect of the latter group in copper activity and selectivity is also discussed. The effect of different preparation methods, different promoters/stabilizers, and the formation mechanism is analyzed. Moreover, the integration of methanol steam reforming process and the high temperature–polymer electrolyte membrane fuel cells (HT-PEMFCs) for the development of clean energy production is discussed.

Green hydrogen can be used as the backbone of a novel energy system and as a feedstock for renewable chemistry. H₂ storage and transport are challenging, but ammonia as a hydrogen carrier could potentially solve these inefficiencies. Many studies focus on high catalytic activities, but the long‐term stability is often insufficiently investigated. This work reports on the stability of a nickel‐based reference catalyst and a coprecipitated Ni/Al₂O₃ catalyst over 800 h time on stream (TOS) in 98% NH₃ at atmospheric pressure. An automated temperature control is necessary to adjust the temperature of the heat source to compensate for the changing heat demand resulting from catalyst activation or deactivation. Under reaction conditions the reference catalyst first undergo an activation phase before reaching its maximum conversion of 91.9% after 250 h TOS followed by a minor decrease in conversion. In comparison, the Ni/Al₂O₃ catalyst shows lower activity and undergo a continuous deactivation due to sintering. Overall, the activity loss at 534 °C amounted to only 1.5% for the reference catalyst and to 13.5% for the Ni/Al₂O₃ catalyst compared with the maximum conversion level. Thus, the Ni‐based reference catalyst proves to be very stable under industrially relevant NH₃ decomposition conditions.

CuCe mixed oxide is one of the most studied catalytic systems for preferential CO oxidation (CO-PrOx) for the purification of hydrogen-rich gas stream. In this study, a series of ceria supports were prepared via a citrates-hydrothermal route by altering the synthesis parameters (concentration and temperature). The resulting supports were used for the preparation of CuCe mixed-oxide catalysts via wet impregnation. Various physicochemical techniques were utilized for the characterization of the resulting materials, whereas the CuCe oxide catalysts were assessed in CO-PrOx reaction. Through the proper modification of the hydrothermal parameters, CeO₂ supports with tunable properties can be formed, thus targeting the formation of highly active and selective catalysts. The nature of the reduced copper species and the optimum content in oxygen vacancies seems to be the key factors behind the remarkable catalytic performance of a CO-PrOx reaction.

The concealed Molai Zn-Pb±(Ag,Ge) stratiform deposit in southeastern Peloponnese is hosted in Triassic intermediate tuffs, ignimbrites and subaerial andesitic flows. The host rocks display trace element signatures of a Supra-Subduction Zone (SSZ) setting. Three ore-forming stages are recognized, with stages I and II related to formation of the epigenetic, stratiform, massive-to-semi-massive ore and a late stage III associated with vein-type mineralization. The O and D isotope geochemistry of gangue chlorite and epidote reveal mixing with fresh meteoric water during the weaning stages of the hydrothermal activity of the late stage II due to uplifting of the hydrothermal system. Sphalerite is the major ore phase, with three different varieties formed during stages I (Sp-I) and II (Sp-II and Sp-III). All sphalerite varieties coexist, depicting gradual change in the chemistry of the ore-forming fluids. Molai ores are characterized by elevated Ag and Ge contents. Tetrahedrite is the major Ag carrier, while among the three sphalerite varieties, early Sp-I comprises the highest Ge contents. The Molai Zn-Pb±(Ag,Ge) deposit is characterized by intermediate features between bimodal felsic massive sulfides and subaerial epithermal systems based on the shallow formation depth, the presence of hydraulic breccias associated with phase separation, the ore formation along high-angle faults, the relatively low ore-forming temperatures below 250 °C obtained from geothermometry, and the absence of the typical structure of bimodal felsic type ores.

Storing energy in molecular form, particularly hydrogen in carbon‐free carriers such as ammonia, is considered a key strategy for future energy systems. The release of hydrogen via ammonia decomposition is a critical step in this context that requires scalable and economically viable catalysts. In this work, spray‐flame synthesis (SFS) was employed to prepare La _{1– x} Sr _x CoO _{3− δ} (0≤ x ≤ 1) nanoparticles (≈ 10 nm), which serve as precursors for SrO‐promoted Co/La ₂ O ₃ catalysts prepared by exsolution. ESR, operando XRD, and ambient pressure photoelectron spectroscopy (APXPS) provide insights into dynamic interfacial restructuring of the catalysts under the harsh ammonia decomposition conditions. The catalysts contain 25 wt% Co and achieve a maximum hydrogen productivity of 108 ·g _Co ⁻¹ ·min ⁻¹ at 500°C for the La _0.75 Sr _0.25 CoO _{3− δ} ‐derived material. The coverage of La ₂ O ₃ with SrO/Sr─OH species under reaction conditions inhibits the migration of La‐based species, which block active Co sites in the absence of the promoter. An excess of Sr, however, promotes the growth of Co particles and reduces the exposed Co surface area. Beyond its structural role, operando APXPS reveals that SrO also influences reaction kinetics by facilitating NH _x decomposition and weakening the binding strength of nitrogen, which is consistent with an electrostatic effect of SrO.