Scientific Papers in SCI

Methanol carbonylation was evaluated over heterogeneous catalysts based on Cu-exchanged zeolitic materials with different topology: Cu@MOR, Cu@FER, and Cu@ZSM-5. Despite the similar Si/Al ratios, it is crucial to acknowledge that the acid strength is influenced by the framework topology, as supported by the NH3-TPD results. This, along with other characterization techniques allowed us to estimate the impact of pore size and pore distribution in these microporous materials on catalytic performance. The channel structure influenced catalytic parameters such as conversion and selectivity. The higher methanol conversion achieved on Cu@FER shows the importance of Bronsted acid sites and redox centres location regarding the topology of the material. Concerning the selectivity, the production of acetic acid was endorsed by the 12-MR (MOR) channels, methyl acetate's production by the 10-MR (FER) channels. Finally, the presence of 6-MR (ZSM-5) channels led to a complete selectivity towards DME production. The reaction mechanism was elucidated via operando DRIFTS-MS and results revealed a bifunctional mechanism in which methanol adsorbs and dehydrates on acidic Bronsted sites and CO is activated over Cu+ species.

The reliance of a future carbon-free horizon is strongly aligned with the long-term energy storage avenues which are completely derived from renewable energy resources. Ammonia with its high energy content and density can perform as a decent candidate for buffering the short-term storage options. However, the current NH₃ production majorly feeding the current huge desire for ammonia is dominated by the conventional nonrenewable Haber–Bosch (H–B) process route, thus continuously damaging the target of carbon neutrality goals. High-purity hydrogen (H₂) gas is an essential precursor for the H–B process; however, it is a significant energy consumer (about 2% of the global energy supply) and contributes over 420 million tons of CO₂/annum. Therefore, the research on the renewable synthesis of nitrogen-based energy carriers (such as ammonia) from the direct electrochemical, photocatalytic, or plasma catalytic processes; its conversion; and utilization to the potential derivatives has been a hot topic in the past few decades. A prospective analysis of the highly appealing processes has been summarized in this study, which could facilitate the adaption of renewable alternatives as an effective approach for zero carbon emission, paving the excellent pathways along the road to the development of nitrogen-based energy technologies, especially the targeted development of ammonia. Further, this Review covers the current and future impacts of the H–B process, the development of aspiring ammonia synthesis routes (via electro, photo, bio, chemical loop, or plasma catalysis), and its conversion and utilization to the renewable derivatives in terms of fabrication of model catalysts, advanced characterization technology, and efficient device design.

This paper provides a review of negative carbon capture technologies. Based on these technologies, here it is proposed an innovative negative emissions power plant combining the generation and storage of energy from biomass, photovoltaic, and concentrated solar power, capturing and recovering CO₂ by producing H₂ or CH₄ as green energy carriers. The main features of the system are i) large-scale energy production system with negative CO₂ emissions; ii) 100% renewable system based on biomass and solar energy with the possibility of integrating other renewables; iii) synergistic integration of processes and systems; iv) recovery of O₂ generated by photovoltaic-driven electrolysis within the process of partial biomass oxycombustion and v) solar-driven limestone calcination. A detailed model of the entire plant is developed to evaluate the integration of the process. The model performance is assessed on an hourly basis throughout the whole year. The base case results show an energy consumption from 1 to 2.1 MJ/kg CO₂ to capture 60–77% of CO₂ emitted from the biomass plant and green methane production of more than 7500 tons/year. The negative emissions associated with the process are -612 kg CO₂/MWh. It justifies the interest in the proposed negative emissions power plant.

This study presents an integrated approach combining aqueous phase reforming (APR) and hydrodeoxygenation (HDO) for the hydrotreatment of guaiacol, a model compound representing lignin-derived phenols in pyrolysis bio-oils. The APR process enables in-situ H2 generation, eliminating the need for an external hydrogen source. We examine the interplay between metal species, the Pt-promoting effect on Ni-Pt catalyst supported on activated carbon (AC), and the choice of hydrogen source (methanol or glycerol). Amongst the monometallic catalysts, a 1% Pt/AC catalyst notably achieved over 96% guaiacol conversion at 300 degrees C with either hydrogen source. Interestingly, when 0.5-1% of the Ni loading is replaced with Pt, the resulting bimetallic Ni-Pt/AC catalysts demonstrate a significant improvement in guaiacol conversion, reaching 70% when methanol is employed as the hydrogen source. Surprisingly, no comparable enhancement in guaiacol conversion is observed when employing glycerol as the hydrogen source. This observation underlines one of the pivotal effects of the hydrogen source on catalyst performance. X-ray photoemission spectroscopy (XPS) pinpointed strong Ni-Pt interactions in the catalyst. It also revealed distinctive electronic features of Ni-Pt/AC, which are favourable for steering selectivity towards cyclohexanol rather than phenol when Pt loading is increased from 0.5 to 1%. Moreover, Pt enhanced catalyst stability by inhibiting the oxidation of Ni sites and mitigating Ni-Pt phase sintering. Overall, our findings offer important insights into integrating APR and HDO processes, the promotion effect of Pt, and the importance of hydrogen source selection in terms of guaiacol conversion and catalyst stability.