Effect of Yb3+ ions on spectroscopic and optical properties of Bi2O3–B2O3–Li2O–PbO glass system

Ytterbium incorporated Bi2O3–B2O3–Li2O–PbO glasses have been found to be suitable for various photonics applications. In the current article, ytterbium (0.5, 1, 1.5, 2.0 and 2.5 mol%) were assorted with Bi2O3–B2O3–Li2O–PbO glass network formed by the conventional melt-quenching process. The XRD, SEM, DTA (DSC), FTIR, Optical absorption and Photoluminescence (PL) techniques employed to explore the detailed optical and structural features of the current glass samples. The analysis of XRD and SEM results confirmed the amorphous nature and their local structural changes perceived by DTA and FTIR results. From absorption data, indirect band gap energies, UE and cut of wavelength values are calculated. It is noticed that the PL properties improved with the increasing ytterbium compositional concentrations up to the level 2.5 mol%. The calculated CIE chromaticity coordinates from PL spectra confirmed quality of the light generated from the as-systemized glasses for LASER production. The obtained experimental results supported the usefulness of the developed glasses in the field of photonics

Near room temperature synthesis of sulfonated carbon nanoplates and their catalytic application

We demonstrate a unique one-pot synthesis approach to obtain sulfonated carbon nanoplates having elongated hexagonal morphology (S-ECN). The S-ECN were synthesized by dehydration of recrystallized sucrose and sodium chloride mixed crystals with concentrated sulfuric acid under ambient conditions. No additional heat treatment or elaborate experimental setup was necessary to obtain graphitic carbon nanoplates. Scanning electron microscopy (SEM) studies showed that presence of NaCl and recrystallization conditions played a crucial role in crystal habit modification of sucrose during recrystallization. Consequently, initial morphology of sucrose crystals was largely preserved in resultant carbon nanostructures. X-ray diffraction, Raman spectroscopy, and transmission electron microscopy studies showed that S-ECN were partially graphitic with wider interplanar spacing compared to standard graphite. The elemental analysis (CHNS) and Fourier transform infrared (FTIR) spectroscopic studies confirm the presence of sulfur in the form of –SO3H group. The catalytic performance of the S-ECN was studied for hydroxyalkylation-alkylation (HAA) reaction of 2-methylfuran with furfural to produce C15 oxygenated hydrocarbon. The S-ECN showed up to 90% conversion of 2-methylfuran. Additionally, an empirical kinetic model was developed to obtain rate constant of HAA reaction and to correlate 2-methylfuran conversion under various reaction conditions. The experimental results matched reasonably well with the calculated 2-methylfuran conversion

Biorefinery Polyutilization Systems: Production of Green Transportation Fuels From Biomass

The green transportation fuels (green gasoline, green diesel, and green jet fuel) (GTF) derived from biomass are quite similar to the petroleum-derived transportation fuels and compatible with existing petroleum refinery infrastructures and combustion engines. The present chapter provides an outline of the various routes for the production of GTF from biomass. In general, the biomass is converted to GTF through thermochemical, chemical, biochemical, and platform chemical-based routes. The current chapter presents an outline of thermochemical conversion processes such as biomass gasification, liquefaction, and pyrolysis and chemical conversion process such as hydrodeoxygenation of triglycerides. The ethanol to gasoline and butanol to gasoline are two important biochemical conversion processes for the production of GTF and discussed in the present chapter. The present chapter also provides an outline of the production of GTF and fuel additives from the platform chemicals such as 5-hydroxymethylfurfural, furfural, and levulinic acid

Role of CeO2/ZrO2 mole ratio and nickel loading for steam reforming of n-butanol using Ni–CeO2–ZrO2–SiO2 composite catalysts: A reaction mechanism

This study presents steam reforming of n-butanol to synthesis gas using high surface area mesoporous Ni–CeO2–ZrO2–SiO2 composite catalysts. The reaction proceeds through a combination of dehydrogenation, dehydration, and cracking reactions with propanal, butanal, and C2–C4 hydrocarbons as intermediate compounds. The ceria forms a solid solution with zirconia, promotes dispersion of nickel, and enhances oxygen storage/release capacity. The carbon conversion to synthesis gas (CCSG) and hydrogen yield are thus enhanced with increasing CeO2/ZrO2 mole ratio up to 1:2 and decreased slightly for higher mole ratios. The CCSG and hydrogen yield are also boosted by increasing the amount of nickel in the catalyst up to 20 wt%. 1:2 CeO2/ZrO2 mole ratio and 20 wt% nickel content are thus deliberated as optimum. The optimum catalyst exhibits stable catalytic performance for about 30 h time-on-stream. The study further presents the effect of temperature and steam/carbon mole ratio on n-butanol steam reforming