A green production process for producing nickel-loaded La_xNa_1−xTaO₃, using a hydrogen peroxide-water based solvent system (HW-derived), is reported. The H₂ evolution of the HW-derived sample is about 1.8 times higher than samples made using ethanol as a solvent. The activity of the sample can be further increased 9.3 times by depositing nanosized nickel as a co-catalyst on the surface of the La_0.02Na_0.98TaO₃. Possible mechanisms of H₂ evolution from pure water and from aqueous methanol solutions using nickel in three states (i.e.Ni metal, NiO oxide, and Ni/NiO core/shell)-La_0.02Na0_0.98TaO₃, are discussed systematically for the first time. It is clearly shown that the activity of hydrogen generation from pure water is in sequence: Ni/NiO > NiO > Ni, whereas the activity sequence with respect to aqueous methanol is: Ni > Ni/NiO > NiO. Metallic Ni presents the most active sites and favors the formation of hydrogen from aqueous methanol. The Ni in Ni/NiO core/shell induce the migration of photogenerated electrons from the bulk to catalyst surface, while NiO act as H₂ evolution site and prevent water formation from H₂ and O₂. The recombination is interrupted by the effective capture of the holes by methanol acting as a sacrificial reagent, thereby leading to higher hydrogen evolution. In contrast, the competition between the recombination and the charge-transfer reaction occurs in pure water leading to a possible back reaction between H₂ and O₂ on the photocatalyst's surface. The photocatalyst synthesis avoids the use of organic solvents and thereby contributes to the environmentally friendly production of hydrogen.

This research aims to evaluate the influence of pyrolysis time and temperature on the composition and properties of bio-oil derived from Mimusops elengi. Experiments were conducted by varying the pyrolysis temperature and time from 400 to 600 °C and 30 to 120 min, respectively. Both pyrolysis temperature and time were found to significantly influence the bio-oil composition. At enhanced pyrolysis temperatures, the bio-oil yield increased while the ash and gas yields decreased. In addition, extended pyrolysis time produced a greater bio-oil yield, indicating that higher temperatures and longer durations promote additional decomposition of biomass. Functional groupings, including alcohols, phenols, ketones, esters, and aromatic compounds in the bio-oil, were identified via FT-IR analysis, indicating that the bio-oil’s diversified chemical properties make it a potential alternative feedstock. GC-MS analysis identified 26 chemical compounds in the bio-oil, of which phenol was the most abundant. However, a high phenol content can diminish bio-oil quality by enhancing acidity, decreasing heating value, and encouraging engine corrosion. Temperature and pyrolysis time are crucial factors in producing bio-oil with the desired chemical composition and physical properties. The maximum yield, 34.13%, was attained after 90 min of operation at 500 °C. The characteristics of the Mimusops elengi bio-oil produced, namely density, viscosity, pH, and HHV were 1.15 g/cm³, 1.60 cSt, 4.41, and 19.91 MJ/kg, respectively, in accordance with ASTM D7544. Using Mimusops elengi as a pyrolysis feedstock demonstrates its potential as an environmentally friendly energy source for a variety of industrial and environmental applications. The yield of bio-oil produced is not optimal due to the formation of tar, which results in the blockage of the output flow during the pyrolysis process.

The research on the use of coconut husk as a solid catalyst for transesterification reaction of Cerbera manghas oil into biodiesel has been done. The aim of this study is to investigate the performance of coconut husk ash for biodiesel production from Cerbera manghas seed oil. Coconut husk is prepared by burning in air to obtain potassium oxide as active phase. The coconut husk is analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD spectrum shows that the peak characteristics of potassium oxide can be observed in the diffractogram. The particle size of the catalyst ranging from 1 - 3 μm with pentagonal structure. The coconut husk ash solid catalyst is used in the transesterification reaction of Cerbera manghas oil in a batch reactor. Biodiesel yield of 88.6% can be achieved over coconut husk ash catalyst, using a 10 wt.% of catalyst, reaction temperature at 3 hours, and a methanol-to-oil ratio of 6: 1. This solid catalyst can be separated easily from the reaction system and not soluble in methanol or methyl esters. The coconut husk ash catalyst is high potential to be developed as one of the solid catalysts to convert Cerbera manghas oil to biodiesel.