Sustainable energy technologies for the Global South: Challenges and solutions toward achieving SDG 7

The United Nations (UN) expectations for 2030 account for a renewable, affordable, and eco-friendly energy future. The 2030 agenda includes 17 different Sustainable Development Goals (SDGs) for countries worldwide. In this work, the 7th SDG: Affordable and Clean Energy, is brought into focus. For this goal, five main challenges are discussed: (i) limiting the use of fossil fuels; (ii) migrating towards diversified and renewable energy matrices; (iii) decentralizing energy generation and distribution; (iv) maximizing energy and energy storage efficiency; and (v) minimizing energy generation costs of chemical processes. These challenges are thoroughly scrutinized and surveyed in the context of recent developments and technologies including energy planning and supervision tools employed in the Global South. The discussion of these challenges in this work shows that the realization of SDG 7, whether partially or in full, within the Global South and global contexts, is possible only if existing technologies are fully implemented with the necessary international and national policies. Among the key solutions identified in addressing the five main challenges of SDG 7 are a global climate agreement; increased use of non-fossil fuel energy sources; Global North assistance and investment; reformed global energy policies; smart grid technologies and real time optimization and automation technologies

A comprehensive spectroscopic, solvatochromic and photochemical analysis of 5-hydroxyquinoline and 8-hydroxyquinoline mono-azo dyes

A series of novel substituted-azo dyes 8-(aryldiazenyl)quinolin-5-ol (5a-i) were synthesized by the coupling reaction of 5-hydroxyquinoline with diazotized aniline derivatives in the presence of NaNO2 in HCl/H2O mixture. The study of the spectroscopic and solvatochromic properties were performed by FT-IR, 1H and 13C-NMR and UV-Visible spectroscopies. The tautomerism of these dyes was studied using the deuteration technique and solvatochromic measurements. Photochromic properties of these 5-hydroxyquinoline azo dyes were also examined via E/Z and Z/E photochemical isomerization reactions and compared with the existing 8-hydroxyquinoline analogous. The novel substituted-azo dyes exhibited higher Z/E thermal isomerization rates and have larger absorbance wavelength range than their 8-hydroxyquinoline analogous, making them potential molecular switches.FCT - Swinburne University of Technology(UID/QUI/00686/2020

Sustainable energy technologies for the Global South: challenges and solutions toward achieving SDG 7

The United Nations (UN) expectations for 2030 account for a renewable, affordable, and eco-friendly energy future. The 2030 agenda includes 17 different Sustainable Development Goals (SDGs) for countries worldwide. In this work, the 7th SDG: Affordable and Clean Energy, is brought into focus. For this goal, five main challenges are discussed: (i) limiting the use of fossil fuels; (ii) migrating towards diversified and renewable energy matrices; (iii) decentralizing energy generation and distribution; (iv) maximizing energy and energy storage efficiency; and (v) minimizing energy generation costs of chemical processes. These challenges are thoroughly scrutinized and surveyed in the context of recent developments and technologies including energy planning and supervision tools employed in the Global South. The discussion of these challenges in this work shows that the realization of SDG 7, whether partially or in full, within the Global South and global contexts, is possible only if existing technologies are fully implemented with the necessary international and national policies. Among the key solutions identified in addressing the five main challenges of SDG 7 are a global climate agreement; increased use of non-fossil fuel energy sources; Global North assistance and investment; reformed global energy policies; smart grid technologies and real time optimization and automation technologies

Molecular docking evaluation of celecoxib on the boron nitride nanostructures for alleviation of cardiovascular risk and inflammatory

Celecoxib (CXB) is a nonsteroidal anti-inflammatory drug (NSAID) that can be used to treat rheumatoid arthritis and ischemic heart disease. In this research, density functional theory (DFT) and molecular docking simulations were performed to study the interaction of boron nitride nanotube (BNNT) and boron nitride nanosheet (BNNS) with CXB and its inhibitor effect on pro-inflammatory cytokines. The calculated adsorption energies of CXB with the BNNT were determined in aqueous phase. The results revealed that adsorption of CXB molecule via its SO2 group on BNNT is thermodynamically favored than the NH2 and CF3 groups in the solvent environment. Adsorption of CXB on BN nanomaterials are weak physisorption in nature. This can be attributed to the fact that both phenyl groups in CXB are not on the same plane and require significant activation energies for conformational changes to obtain greater H-π interaction. Both BNNT and BNNS materials had huge sensitivity in electronic change and short recovery time during CXB interaction, thus having potential as molecular sensor and biomedical carrier for the delivery of CXB drug. IL-1A and TNF-α were implicated as vital cytokines in diverse diseases, and they have been a validated therapeutic target to manage cardiovascular risk in patients with inflammatory bowel disease. A molecular docking simulation confirms that the BNNT loaded CXB could inhibit more pro-inflammatory cytokines including IL-1A and TNF-α receptors as compared to BNNS loaded to CXB

A robust computational investigation on C₆₀ fullerene nanostructure as a novel sensor to detect SCNˉ

This study explored on the adsorption properties and electronic structure of SCNˉ via density functional theory analysis on the exterior surfaces of C₆₀ and CNTs using B3LYP functional and 6-31G** standard basis set. Then adsorption of SCNˉ through nitrogen atom on the C60 fullerene is electrostatic (₋48.02 kJ molˉ1) in comparison with the C₅₉Al fullerene that shows covalently attached to fullerene surface (₋389.10 kJ mol̄ˉ1). Our calculations demonstrate that the SCNˉ adsorption on the pristine and Al-doped single-walled CNTs are ₋173.13 and ₋334.43 kJ molˉ1, indicating that the SCNˉ can be chemically bonded on the surface of Al-doped CNTs. Moreover, the adsorption of SCNˉ on the C₆₀ surface is weaker in comparison with C₅₉B, C₅₉Al, and C₅₉Ga systems but its electronic sensitivity improved in comparison with those of C₅₉B, C₅₉Al, and C₅₉Ga fullerenes. The evaluation of adsorption energy, energy gap, and dipole moment demonstrates that the pure fullerene can be exploited in the design practice as an SCNˉ sensor and C₅₉Al can be used for SCNˉ removal application

Improved anti-inflammatory and anticancer properties of celecoxib loaded zinc oxide and magnesium oxide nanoclusters: A molecular docking and density functional theory simulation

Present study offers great prospects for the adsorption of anti-inflammatory celecoxib molecule (CXB) over the surface of zinc oxide (Zn12O12) and magnesium oxide (Mg12O12) nanoclusters in several environments by performing robust theoretical calculations. Density functional theory (DFT), time-dependent density functional theory (TDDFT) and molecular docking calculations have been extensively carried out to predict the foremost optimum site of CXB adsorption. It has been observed that the CXB molecule prefers to be adsorbed by its SO2 site on the Zn-O and Mg-O bonds of the Zn12O12 and Mg12O12 nanoclusters instead of NH2 and NH sites, where electrostatic interactions dominate over the bonding characteristics of the conjugate complexes. Furthermore, the presence of interactions between the CXB molecule and nanoclusters has also been evidenced by the UV–Vis absorption spectra and IR spectra. Molecular docking analysis has revealed that both adsorption states including CXB/Zn12O12 and CXB/Mg12O12 have good inhibitory potential against protein tumor necrosis factor alpha (TNF-α) and Interleukin-1 (IL-1), and human epidermal growth factor receptor 2 (HER2). Hence they might be explored as efficient TNF-α, IL-1, and HER2 inhibitors. Hence from the study, it can be anticipated that these nanoclusters can behave as an appropriate biomedical carrier for the CXB drug delivery

Kinetic modeling of gas-phase phenol hydrodeoxygenation over Ag/TiO2 catalyst via TGA-FTIR based microreactor / Andrew Ng Kay Lup

Bio-oil produced from biomass pyrolysis is a potential source for liquid fuel. However, bio-oil has high oxygen content due to its complex mixture of oxygen-containing compounds which results in deleterious properties such as lower heating value, corrosion and chemical instability of liquid fuel. Phenolics are some of the major O-containing constituents commonly found in lignocellulosic biomass derived bio-oil. Thus, phenolic hydrodeoxygenation (HDO) is a process required for bio-oil upgrading into high quality liquid fuel. In this study, gas-phase hydrodeoxygenation of phenol over Ag/TiO2 catalyst at atmospheric pressure was conducted as a model compound approach in investigating the reaction mechanism and kinetics of oxygen removal from phenolics. Physicochemical properties of Ag/TiO2 catalyst were investigated to explore its potential as hydrodeoxygenation catalyst. The results showed that the metal-support interaction of Ag/TiO2 enabled hydrogen spillover phenomenon and synergistic interaction of acid and metal sites which are fundamental in catalyzing adsorption and activation of phenolics and hydrogen during hydrodeoxygenation. Reduction study of Ag/TiO2 by hydrogen also showed that Ag2O undergoes single-step reduction to form Ag which can be described using unimolecular decay model. Sample encapsulation technique was also proposed in this study to lengthen the release of vaporized phenol sample in microreactor. The delayed volatiles release phenomenon was enhanced by using metal capsule with higher material hardness and smaller surface area for sample evaporation. By using cylindrical tin capsule, significant release of vaporized phenol was extended up to 454—554 K which is above its boiling point. This finding is useful in enabling better catalyst activation and kinetic study of catalytic solid-gas reaction over a larger temperature range but at a fixed reactant amount. FTIR and GC-MS analyses showed the conversion of phenol into benzene as major product over Ag/TiO2 catalyst at atmospheric pressure condition. The proposed kinetic model for the phenol HDO network over Ag/TiO2 confirmed the occurrence of phenol hydrogenolysis and hydrogenation; cyclohexanol dehydration and hydrogenation of benzene and cyclohexene. The reaction rates increase with the following order: r1 (phenol hydrogenolysis) < r2 (phenol hydrogenation) < r5 (benzene hydrogenation) < r3 (cyclohexanol dehydration) < r4 (cyclohexene hydrogenation). Both phenol hydrogenolysis and hydrogenation steps are the respective rate-limiting steps for DDO (direct deoxygenation) and HYD (hydrogenation-dehydration) pathways of phenol hydrodeoxygenation over Ag/TiO2. Application of transition state theory has also indicated formation of more orderly activated complexes in the elementary reaction steps as indicated by the negative entropy change of activation. The proposed kinetic model was able to describe quantitative and qualitative observations in this work with a reasonable agreement and would be a useful tool for kinetic and mechanistic understanding of surface reactions of phenol HDO over supported transition metal catalysts. Successive hydrodeoxygenation runs (4 h) showed no significant degradation in catalytic and physicochemical properties of Ag/TiO2 catalyst. The accumulation of oxidized Ag metal species and coke deposits on Ag/TiO2 catalyst after each HDO run can be removed via H2-activation and calcination in air at 553 K with at least 98.9% removal efficiency

Delayed volatiles release phenomenon at higher temperature in TGA via sample encapsulation technique

Thermogravimetric analysis (TGA) for solid-gas reactions is well formalized and of ubiquitous use. However, the use of volatile samples in TGA often results in pre-loss of volatile sample by evaporation prior to reaching the specified thermal conditions of analysis. Therefore, sample encapsulation method was proposed as an innovative technique to address this issue. This technique was shown to provide a continuous and delayed release of vaporized samples over the range of elevated temperature through the progressive loosening of the hermetic seal of metal capsule. This effect can be enhanced by using capsule with higher material hardness and smaller surface area for sample evaporation. Application of this method in catalytic phenol reduction has shown an increase in benzene yield from 19.2 mol% to 46.5 mol% when phenol is encapsulated by tin cylinder. Based on these findings, delayed volatiles release phenomenon may lead to further opportunities in the area of thermochemical kinetics study for fuel processing such as gasification, carbonization, reforming or petrochemical reactions that involve catalyst activation at high temperature and use of volatile samples such as fuel model compounds in TGA setup

Synergistic interaction of metal–acid sites for phenol hydrodeoxygenation over bifunctional Ag/TiO2 nanocatalyst

The use of silver metal for hydrodeoxygenation (HDO) applications is scarce and different studies have indicated of its varying HDO activity. Several computational studies have reported of silver having almost zero turnover frequency for HDO owing to its high C–O bond breaking energy barrier and low carbon and oxygen binding energies. Herein this work, titania supported silver catalysts were synthesized and firstly used to examine its phenol HDO activity via experimental reaction runs. BET, XRD, FESEM, TEM, EDX, ICP–OES, Pyridine-FTIR, NH 3 -TPD and H 2 -TPD analyses were done to investigate its physicochemical properties. Phenomena of hydrogen spillover and metal–acid site synergy were examined in this study. With the aid of TiO 2 reducible support, hydrogen spillover and metal–acid site interactions were observed to a certain extent but were not as superior as other Pt, Pd, Ni-based catalysts used in other HDO studies. The experimental findings showed that Ag/TiO 2 catalyst has mediocre phenol conversion but high benzene selectivity which confirms the explanation from other computational studies. © 2018 Elsevier B.V

Delayed volatiles release phenomenon at higher temperature in TGA via sample encapsulation technique

Thermogravimetric analysis (TGA) for solid-gas reactions is well formalized and of ubiquitous use. However, the use of volatile samples in TGA often results in pre-loss of volatile sample by evaporation prior to reaching the specified thermal conditions of analysis. Therefore, sample encapsulation method was proposed as an innovative technique to address this issue. This technique was shown to provide a continuous and delayed release of vaporized samples over the range of elevated temperature through the progressive loosening of the hermetic seal of metal capsule. This effect can be enhanced by using capsule with higher material hardness and smaller surface area for sample evaporation. Application of this method in catalytic phenol reduction has shown an increase in benzene yield from 19.2 mol% to 46.5 mol% when phenol is encapsulated by tin cylinder. Based on these findings, delayed volatiles release phenomenon may lead to further opportunities in the area of thermochemical kinetics study for fuel processing such as gasification, carbonization, reforming or petrochemical reactions that involve catalyst activation at high temperature and use of volatile samples such as fuel model compounds in TGA setup