Dibenzyltoluene/perhydro-dibenzyltoluene (H₀DBT/H₁₈DBT) is considered a promising liquid organic hydrogen carrier (LOHC) pair for the storage and transportation of green hydrogen (H₂). However, at the point of use, the catalytic dehydrogenation of H₁₈DBT is still limited by mass transport limitations. To address this issue, the dehydrogenation of H₁₈DBT was successfully conducted on Pt/Al₂O₃-coated foams in both an unstirred tank reactor and a fixed-bed reactor (FBR). A performance comparison between coated foams and pellets in the tank reactor revealed that H₂ productivities were 12–59% higher in the foam-based reactor than in the pellet-based reactor. Since the textural properties of the foam-supported and pellet-based catalysts were similar, the higher degree of dehydrogenation (DoD) and H₂ productivity achieved by the former were attributed to the geometric properties of the foam structure. Long-term tests performed in the FBR demonstrated the ability of the coated foams to maintain steady activity for >16 h on stream. However, the single-pass DoDs achieved were 34–38%. By recycling the partially dehydrogenated products three times into the FBR, the DoD improved to 63%. The results of this study demonstrated the capabilities of the coated foams in the process intensification of LOHC dehydrogenation reactors.

This work presents an experimental and modelling evaluation of the preferential oxidation of CO (CO PROX) from a H₂-rich gas stream typically produced from fossil fuels and ultimately intended for hydrogen fuel cell applications. A microchannel reactor containing a washcoated 8.5 wt.% Ru/Al₂O₃ catalyst was used to preferentially oxidise CO to form CO₂ in a gas stream containing (by vol.%): 1.4% CO, 10% CO₂, 18% N₂, 68.6% H₂, and 2% added O₂. CO concentrations in the product gas were as low as 42 ppm (99.7% CO conversion) at reaction temperatures in the range 120–140 °C and space velocities in the range 65.2–97.8 NL g_cat⁻¹ h⁻¹. For these conditions, less than 4% of the H₂ feed was consumed via its oxidation and reverse water-gas shift. Furthermore, a computational fluid dynamic (CFD) model describing the microchannel reactor for CO PROX was developed. With kinetic parameter estimation and goodness of fit calculations, it was determined that the model described the reactor with a confidence interval far greater than 95%. In the temperature range 100–200 °C, the model yielded CO PROX reaction rate profiles, with associated mass transport properties, within the axial dimension of the microchannels––not quantifiable during the experimental investigation. This work demonstrates that microchannel reactor technology, supporting an active catalyst for CO PROX, is well suited for CO abatement in a H₂-rich gas stream at moderate reaction temperatures and high space velocities.

The era of considering carbon dioxide (CO₂) as a waste stream has passed. New methods of utilising CO₂ as a carbon feedstock are currently the focus of extensive research efforts. A fixed-bed reactor containing a commercial Cu/ZnO/Al₂O₃ catalyst washcoated on a Cu foam was used for the synthesis of methanol through direct CO₂ hydrogenation. Catalytic activity tests in this reactor were conducted at reaction pressures of 30 and 50 bar, temperatures in the range 190–250 °C, and weight hourly space velocities (WHSV) in the range 1.125–2.925 NL g_cat⁻¹ h⁻¹. The best reactor performance was recorded at 50 bar pressure: CO₂ conversion and methanol selectivity of 27.46% and 82.97%, respectively, were obtained at 240 °C and 1.125 NL g_cat⁻¹ h⁻¹. Increasing the WHSV to 2.925 NL g_cat⁻¹ h⁻¹ resulted in a twofold increase in methanol weight time yield (WTY) to 0.18 g_MeOH g_cat⁻¹ h⁻¹ and a decrease in methanol selectivity to 70.55%. The results presented in this investigation provide insight into the performance of a bench-scale reactor in which mass transfer limitations are non-negligible and demonstrate that metal foams are promising catalyst support structures for CO₂ hydrogenation towards methanol production.