The CO₂ consumption of flue gas for methanol production is investigated as an alternative for conventional, energy-intensive CO₂ capture methods in this study. Aspen HYSYS v12.1 was used to model the tri-reforming process, which aims to lower the carbon impact of traditional methods by converting CO₂ into methanol. With a stoichiometric number (Sn) of 2.216, the ideal H₂:CO ratio was determined to be 2.293. To obtain high CO₂ conversion rates at high temperatures, guarantee the required ratios, and reduce carbon formation on the catalyst, a nickel-based catalyst was employed in the tri-reforming process. With a methanol purity of 99.1%, methanol synthesis used a Cu/ZnO/Al₂O₃ commercial catalyst for CO hydrogenation, which significantly reduced carbon emissions to 0.032 kg CO₂ per kg of methanol.

This study discovered that Ni-based catalysts could accomplish 80–95% CH₄ conversion and good syngas selectivity at temperatures between 800 and 900°C and atmospheric conditions to moderate pressures while maintaining an ideal H₂/CO ratio of about 2.0–2.5. But because carbon deposition happened at rates of about 2–10 mgC/g-cat/h, more steam was needed for steam reforming in order to increase CO₂ conversion and decrease coke development. The highest H₂/CO ratio and the highest CH₄ and CO₂ conversion rates were obtained when operating at 850°C and 1 atm. Under conditions similar to those of natural gas-based power plants, simulation results demonstrated effective CO₂-to-methanol conversion with flue gas flow rates of 1000 kmol/h and 10 mol% CO₂. In order to optimize the reforming reactions and perhaps reduce reactor volume and mitigate high operating pressures, further reactor parameter optimization is advised, including introducing O₂ and H₂O. This study underlines the need for more research into process economics and scalability for large-scale implementation, while also highlighting the potential of tri-reforming for sustainable methanol synthesis from power plant emissions.

The valorization of underutilized organic waste into high-value polymeric materials is a growing topic in Thailand's industrial polymer production sector, addressing critical ecological challenges. Lignin, an abundant aromatic biopolymer found in agricultural wastes like coconut shells, has significant potential for producing high-value chemicals and contributing to a circular economy. However, its complex structure, characterized by sensitive C-O bonds, necessitates selective extraction to develop useful aromatic molecules for biotechnological applications. This study investigated the catalytic performance of hydrochloric acid in the organosolv treatment of coconut shells. Lignin was hydrolyzed in a 70% ethanol solution with 2.2% (w/v HCl) at 190 °C for 90 min, yielding up to 96% lignin. The chemical structure of lignin was characterized and discussed. Fourier-transform infrared (FT-IR) spectroscopy revealed a high intensity of hydroxyl groups, indicating the breakdown of lignin–carbohydrate linkages and interlinkages. The lignin consists of syringyl (S), guaiacyl (G), and p-hydroxyphenyl (H) units, classifying it as a grass-type (HGS). Methoxyl groups were also identified in the coconut shell monomeric units, suggesting minimal modification of the native lignin structure. Additionally, the resulting β–O–4 linkage-rich lignin fractions exhibited enhanced biological reactivity compared to commercially available lignin, demonstrating UV absorption capacity and antibacterial properties. This work proposes a sustainable biorefinery approach to transform agro-wastes into valuable resources through lignin extraction, facilitating the creation of bioactive compounds for innovative applications in cosmetics and health products.

Industrial catalysts are accelerating the global transition toward renewable energy, serving as enablers for innovative technologies that enhance efficiency, lower costs, and improve environmental sustainability. This review explores the pivotal roles of industrial catalysts in hydrogen production, biofuel generation, and biomass conversion, highlighting their transformative impact on renewable energy systems. Precious-metal-based electrocatalysts such as ruthenium (Ru), iridium (Ir), and platinum (Pt) demonstrate high efficiency but face challenges due to their cost and stability. Alternatives like nickel-cobalt oxide (NiCo₂O₄) and Ti₃C₂ MXene materials show promise in addressing these limitations, enabling cost-effective and scalable hydrogen production. Additionally, nickel-based catalysts supported on alumina optimize SMR, reducing coke formation and improving efficiency. In biofuel production, heterogeneous catalysts play a crucial role in converting biomass into valuable fuels. Co-based bimetallic catalysts enhance hydrodeoxygenation (HDO) processes, improving the yield of biofuels like dimethylfuran (DMF) and γ-valerolactone (GVL). Innovative materials such as biochar, red mud, and metal–organic frameworks (MOFs) facilitate sustainable waste-to-fuel conversion and biodiesel production, offering environmental and economic benefits. Power-to-X technologies, which convert renewable electricity into chemical energy carriers like hydrogen and synthetic fuels, rely on advanced catalysts to improve reaction rates, selectivity, and energy efficiency. Innovations in non-precious metal catalysts, nanostructured materials, and defect-engineered catalysts provide solutions for sustainable energy systems. These advancements promise to enhance efficiency, reduce environmental footprints, and ensure the viability of renewable energy technologies.

Addressing the long-term environmental impact of chemical production has become a global challenge, emphasizing the need for sustainable and greener alternatives. In this study, a mesostructured silica was synthesized using a biomass-derived molding agent. The synthesized material was characterized by means of N2 adsorption and desorption isotherms, Transmission Electron Microscopy (TEM) and Infrared Spectroscopy (FT-IR). A heterogeneous biocatalyst was developed by immobilizing the lipase from Pseudomonas fluorescens onto the material, aiming to produce isoamyl acetate—a banana-flavored compound that is widely used in the flavoring industry—as a more sustainable alternative. The catalytic activity of the heterogeneous biocatalyst was evaluated in the transesterification of vinyl acetate with isoamyl alcohol at 40 °C in three systems: a thermosized orbital stirrer, a microwave reactor and ultrasound. The best performance was achieved with a material that was prepared with 96h of immobilization between the enzyme and support at 400 mg_enzyme/g_support, achieving conversion rates of 28 %, 28.5 % and 32.5 % at 2h of reaction in the three systems, respectively. Thus, compared to traditional mechanical agitation and microwave methods, ultrasound technology improves the process productivity significantly, being a powerful tool for improving a biocatalyst's performance in this type of reaction. This research highlights the robustness of lipases in esterification reactions, showcasing their ability to adapt to different reaction systems and laying the groundwork for future studies aimed at the more sustainable production of high-value-added products in fine chemistry.

Guanabenz, a marketed antihypertensive drug, is primarily sold in its monoprotonated form, while its free base form has received little attention. Interestingly, under physiological conditions of temperature and pH, approximately 16% of guanabenz exists in its free base form. Our group recently discovered that the free base form of guanabenz is a tautomeric form of guanylhydrazones, known as azines.¹ Notably, guanabenz prominently adopts the azine tautomeric state, as confirmed through both experimental and theoretical studies. This discovery has sparked a new research direction in our lab, focusing on this previously overlooked class of molecules: 1,1-diaminoazines. The unique characteristics of 1,1-diaminoazines directed us to employ them in different research areas of chemistry. 1,1-Diaminoazines are known to have applications in medicinal chemistry, material chemistry, catalysis, organic synthesis, etc.² The presence of electrophilic and nucleophilic sites in the same molecule makes 1,1-diaminoazines a unique substrate (I) for cycloaddition reactions synthesising dihydropyrazoles and different types of substituted triazoles.³ The presence of a) the conjugated double bonds, (b) the many active hydrogen atoms, (c) the N2 centre in 1,1-diaminoazines acting as a proton acceptor, and (d) the iminic C4 acting as a hydrogen bond donor makes this molecule a potential bifunctional organocatalyst.⁴ To prove the same, this molecule has been used to catalyse various types of Michael addition reactions.^5,6 Successfully, it has been utilised in C-P and C-C bond formation. Furthermore, it has facilitated the aldol/cyclisation cascade reactions, efficiently generating small heterocycles.⁷ Additionally, it has been proven efficient in carrying out different multi-component reactions (MCRs) to generate bioactive scaffolds such as pyranopyrazoles. Quantum chemical studies have been carried out to prove the mechanistic insights and to further enhance its utility, and efforts are currently underway to develop an asymmetric version of this catalyst. This modification aims to unlock its potential for enantioselective transformations, paving the way for the synthesis of complex molecules and expanding its applicability in medicinal chemistry. Other than this, 4-pyridyl-4 methyl-1,1-diaminoazine was employed to generate the pincer complex with Pd(OAc)₂. The application of the complex in catalysing the medicinally important scaffold (e.g., benzimidazoles, quinolines, quinoxazolinones) synthesis using the ADC mechanism has been reported.⁸

[1] Cryst. Growth Des. 2019, 19, 3183 [2] Org. Biomol. Chem. 2019, 17, 8486. [3] J. Org. Chem. 2021, 86, 7659 [4] Chem. Comm. 2021, 57, 11717 [5] New J. Chem., 2023, 47, 1998 [6] Tetrahedron Lett., 2023, 122, 154505 [7] ChemistrySelect., 2024, 9, e202405002 [8] Org. Biomol. Chem., 2025, 23, 343

The hydrogenation of carbon dioxide to C₂, C₃, and C₄ paraffins was examined by using hybrid catalysts containing a Cu-Zn catalyst with Zr-modified H-ZSM-5 zeolite, or Pd-modified β zeolite with H-ZSM-5, or Pt/SiO₂ with H-ZSM-5, or Pd/SiO₂ with H-ZSM-5 β zeolite. Various factors which affect catalyst activities were examined such as reaction temperature, pressure, and the influence of the SiO₂/Al₂O₃ ratio. The tests were conducted at 260-300^°C, 2-3 MPa, a W/F of 10 g.h/mol, and with a H₂/CO₂ mole ratio of 3. The influence of the SiO₂/Al₂O₃ ratio on H-ZSM-5 zeolite played an important role in hydrocarbon distribution. When H-ZSM-5 was used on the zeolite with low alumina content (SiO₂/Al₂O₃=100), the product contained olefins and dimethyl ether with a large amount of C₅ and C₆, whereas that for the zeolite with high alumina content (SiO₂/Al₂O₃=40) showed an excellent conversion of carbon dioxide to hydrocarbon. Under mild temperature at 280°C, CO₂ conversion reached 23% with a hydrocarbon selectivity as high as 80%, while keeping the dry gas (CH₄) selectivity below 1% by using the hybrid catalysts. When Pd/SiO₂ with β zeolite was used for the hybrid catalysts, butane was produced with a high selectivity over 50% at 280°C and 3 MPa with a small amount of coke deposition.

The selective hydrogenation of α,β-unsaturated carbonyl compounds (enones) versus isolated double bonds is a reaction of considerable interest in organic synthesis, particularly in the pharmaceutical and fine chemical industries. Previous studies have elucidated the mechanism of this reaction, which is catalyzed by the Cp*Rh(2-(2-pyridyl)phenyl)H complex^1,2. However, computational research has primarily focused on substrates containing a single reactive group, neglecting systems with both enone and olefin functionalities². Moreover, the origins of the preference for enone hydrogenation remain insufficiently explored.

In this study, DFT calculations were employed to investigate the key electronic and geometric features enabling the selective hydrogenation of a dual-functionality substrate, catalyzed by the Cp*Rh(2-(2-pyridyl)phenyl)H complex. The analysis integrated two complementary approaches: (1) an electron density-focused framework, including charge transfer and QTAIM/ELF analyses at critical points along the reaction force profile, and (2) quantum mechanical methods such as NBO analysis of donor–acceptor interactions and interference energy evaluations of the complex–substrate system. Additionally, coordination and deformation energies of the catalyst–substrate complex were compared for dual substrates and for substrates containing only one functionality.

The results reveal that the selective hydrogenation of enones over olefins is governed by distinct substrate–catalyst interactions, influenced by both steric and electronic factors. The interplay between electrostatic and quantum phenomena elucidates the preference for enone hydrogenation and provides insights into the coupling between electron and proton transfers along the reaction pathway. These findings suggest modifications to the ligand structure to further enhance the selective hydrogenation of enones, expanding the versatility of Rh-catalyzed transformations in synthetic chemistry.

1. Gu, Y., Norton, J. R., Salahi, F., Lisnyak, V. G., Zhou, Z., & Snyder, S. A. (2021). Highly selective hydrogenation of C═C bonds catalyzed by a rhodium hydride. Journal of the American Chemical Society, 143(25), 9657-9663.
2. Zhang, Y., & Li, X. (2022). Computational Mechanism Investigation of C=C Bond Hydrogenation Catalyzed by Rhodium Hydride. ChemPhysChem, 23(18), e202200562.

The aim of this work is a comprehensive study of the structural and electronic properties of the trirutile compound FeSb₂O₆. The quantum DFT approximation used for this research was applied to iron antimonate oxide, which has a well-defined trirutile structure with the space group P42/mnm (136). It crystallizes in a tetragonal lattice, featuring unit-cell parameters of a = 0.466 nm and c = 0.924 nm. The structural characteristics of a material can be thoroughly investigated without the need for physical measurements by employing optimized first-principles computational methods. In this case, the CASTEP code, integrated within the Material Studio software suite, was utilized based on a pseudo-potential plane-wave approach. In this study, the geometrical optimization of FeSb₂O₆ was conducted using a semi-local generalized gradient approximation (GGA), specifically employing the Perdew–Burke–Ernzerhof (PBE) exchange–correlation functional. Additional functionals used include the PBE for solids (PBESOL), Perdew-Wang91 (PW91), the revised PBE (RPBE), and the local density approximation (LDA-CAPZ). After optimization, both the band gap values and the density of states (DOS) of FeSb₂O₆ were calculated to gain deeper insight into its electronic properties. The electronic properties of FeSb₂O₆ were determined by examining its electronic band structure and DOS, establishing it as a narrow-gap semiconductor with a direct band gap, making it promising for potential electronic applications.

The π-conjugated structures of organic photovoltaic cells offer a viable answer to meet the growing need for renewable energy sources. This research investigates how the addition of benzocyclic groups such as benzofuran (BF), benzoxazole (BFz), indole (ID), benzimidazole (IDz), benzothiophene (BT), and benzothiazole (BTz) to porphyrin systems increases their electron donation potential for use in photovoltaic devices. The electronic, optical, and thermodynamic properties of seven molecular configurations (P, PID, PIDz, PBF, PBFz, PBT, and PBFz) were assessed through density functional theory (DFT) using the B3LYP/6-31G+(d,p) basis set. A steady reduction in the free energy points to greater stability, alongside changes in the dipole moment, demonstrates substantial charge polarization effects. An analysis of the HOMO-LUMO gaps demonstrates the enhanced electronic stability in PIDz, PBFz, PBT, and PBTz, which is vital for charge transfer optimization and reactivity improvements. PBFz and PBTz demonstrate promising DOS profiles that maximize the donor–acceptor overlap and electronic transitions, leading to a superior solar material performance. The N-H, C-H, and C=C vibrational modes play a key role in the charge delocalization and light absorption, which are essential to the photovoltaic performance. The optical measurements reveal a red shift, with λmax from P at 359.6 nm toward PID at 405.0 nm, while PBTz shows the maximum absorption levels, which demonstrates improved π → π* transitions, leading to enhanced light-harvesting capabilities. The transition density matrix, alongside exciton binding energy studies, reveals PBFz and PBTz as the top choices for solar cell technologies because of their superior charge separation abilities and excitonic features. The NBO analysis confirms PBFz and PBTz as the top materials for organic photovoltaics and nonlinear optics while providing a basis for ongoing optimization and device exploration.

Semiconductor-based photocatalysis presents a promising solution to the global energy crisis and environmental pollution challenges. Since the groundbreaking discovery of graphitic carbon nitride (g-C₃N₄) in 2009 for visible light-driven photocatalytic water splitting, g-C₃N₄-based photocatalysis has emerged as a highly active area of research. Herein, the structural modification of pristine g-C₃N₄ isexplored to enhance its photocatalytic efficiency, employing density functional theory (DFT) with the widely adopted B3LYP/6-31g(d) theory. Furthermore, the band structure for the periodic system was determined using GGA-PBE functionals. This study investigated the effects of functionalizing g-C₃N₄ with different grafting agents, including benzofuran (BF), benzoxazole (BFz), indole (ID), and benzimidazole (IDz). Thermodynamic analyses revealed notable changes in free energy, indicating the improved binding possibility of the modified materials. Frontier molecular orbital analyses showed reduced HOMO-LUMO gaps, correlated with enhanced reactivity and improved charge transfer properties. Dipole moment analyses confirmed increased polarity, promoting higher photocatalytic activity. Band structure and density of states (DOS) analyses demonstrated shifts in energy levels conducive to visible light absorption. Theoretical FT-IR and Raman spectra confirmed successful functionalization by identifying characteristic bonds and vibrational modes. In contrast, UV-vis absorption spectra revealed a redshift absorption of modified g-C₃N₄, indicating improved light absorption. These findings highlight the potential of grafted g-C₃N₄ materials for efficient photocatalytic applications, offering a promising approach to address energy and environmental challenges.