RAWESH KUMAR - Profile on Academia.edu (2025)

Recycling calcium oxide nanoparticles for sustainable biodiesel production from nonedible feedstock Argemone mexicana L

Biofuels

Scientific Reports, Jul 12, 2023

Biomass waste streams are a possible feedstock for a range of eco-friendly products and a crucial... more Biomass waste streams are a possible feedstock for a range of eco-friendly products and a crucial alternative energy source for achieving carbon neutrality; therefore, the efficient management of biomass waste has taken on a greater significance in recent years. Due to its well-comparable physicchemical properties with fossil diesel, biodiesel is a potential substitute for fossil fuel. This study aimed to synthesize biodiesel from the widely available non-edible seed oil of Sisymbrium irio L. (a member of the Brassicaceae family) via a transesterification procedure over a homemade TiO 2 catalyst. At 1:16 oil to methanol ratio, 93% biodiesel yield was obtained over 20 mg catalyst at 60 °C and 60 min. The ASTM methods were used to analyze the fuel properties. The quantitative and qualitative analysis was performed by FT-IR, GC-MS, and NMR spectroscopy. GC-MS study confirms 16 different types of fatty acids of methyl esters. FT-IR analysis showed important peaks that confirm the successful occurrence of biodiesel. 1 H-NMR and 13 C-NMR showed important peaks for converting triglycerides into corresponding FAMEs. The acid value (0.42 mg KOH/mg/kg), flash point (106 °C), and water content (0.034) of biodiesel are below the specified limit of ASTM D6751 whereas kinetic viscosity (3.72 mm 2 /s), density (0.874 kg/L), cloud point (− 4.3 °C) and pour point (− 9.6 °C) and high heating value (41.62 MJ/kg) fall within the specified range of ASTM D6751 test limit. The Unsaturation degree and oxidative stability of biodiesel are above ASTM D6751 test limit. The physic-chemical properties of the SIB confirm that it is eco-friendly fuel and a competitive source for manufacturing biodiesel on a commercial scale. Furthermore, the SIB is engine friendly and has good fuel efficacy. Abbreviations SIB Sisymbrium irio Biodiesel TiO 2 Titanium dioxide FFA Free fatty acid SEM Scanning electron microscopy XRD X-rays diffraction H and C-NMR Nuclear magnetic resonance GC-MS Gas chromatography mass spectrometry FT-IR spectroscopy Fourier transform infrared spectroscopy ASTM

Reforming of methane: Effects of active metals, supports, and promoters

Catalysis Reviews-science and Engineering, May 27, 2023

Enhanced direct methanation of CO2 using Ni-based catalysts supported on ZrO2, CeO2-ZrO2, and La2O3-ZrO2: The effect of support material on the reducible NiO-interacted species and catalytic activity

Molecular Catalysis

Rh promoted Ni over yttria–zirconia supported catalyst for hydrogen‐rich syngas production through dry reforming of methane

Energy Science & Engineering

Rh‐promoted YZr‐supported Ni catalyst (5Ni/YZr) is investigated for DRM and characterized with X‐... more Rh‐promoted YZr‐supported Ni catalyst (5Ni/YZr) is investigated for DRM and characterized with X‐ray diffraction, Raman, infrared spectroscopy, cyclic reduction–oxidation–reduction temperature programmed experiment, thermogravimetry, and transmission electron microscope. Over 5Ni/YZr, some active sites become inactive under the CO2 stream and limit H2 yield to ∼71%. Upon 4 wt% Rh addition over 5Ni/YZr; more than one type of stable active sites (Rh and Ni) generates, moderate basic sites are enhanced, wide ranges of CO2‐interacted surface species (especially bidentate CO2‐adsorbed species) are grown and graphitic carbon proportion over spent catalyst declines. Thisresulted in 87.35% H2 yield and 86.73% CO yield up to 420 min. 5Ni4Rh/YZr catalyst maintains ∼80% H2 yield at the end of 27 h of DRM reaction.

International Journal of Chemical Engineering

A better understanding of the reaction mechanism and kinetics of dry reforming of methane (DRM) r... more A better understanding of the reaction mechanism and kinetics of dry reforming of methane (DRM) remains challenging, necessitating additional research to develop robust catalytic systems with high catalytic performance, low cost, and high stability. Herein, we prepared a zirconia-alumina-supported Ni-Fe catalyst and used it for DRM. Different partial pressures and temperatures are used to test the dry reforming of methane reaction as a detailed kinetic study. The optimal reaction conditions for DRM catalysis are 800°C reaction temperature, 43.42 kPa CO2 partial pressure, and 57.9 kPa CH4 partial pressure. At these optimal reaction conditions, the catalyst shows a 0.436 kPa2 equilibrium constant, a 0.7725  m o l C H 4 /gCat/h rate of CH4 consumption, a 0.00651  m o l C H 4 /m2/h arial rate of CH4 consumption, a 1.6515  m o l H 2 /gCat/h rate of H2 formation, a 1.4386 molCO/gCat/h rate of CO formation. This study’s findings will inspire the cost-effective production of robust catalyti...

Promoted Yttria-Zirconia Supported Ni Catalyst for Syngas Production Through Dry Reforming of Methane

The influence of Ni stability, redox, and lattice oxygen capacity on catalytic hydrogen production via methane dry reforming in innovative metal oxide systems

Energy Science & Engineering

Finding a robust catalytic system for hydrogen production via dry reforming of methane (DRM) rema... more Finding a robust catalytic system for hydrogen production via dry reforming of methane (DRM) remains a challenge. Herein, MNi0.9Zr1−xYxO3 (M = Ce, La, and La0.6Ce0.4; x = 0.00, 0.05, 0.07, and 0.09) catalyst was prepared by the sol–gel method, tested for DRM and characterized by surface area and porosity, X‐ray diffraction, H2‐temperature programmed reduction, thermogravimetry, and transmission electron microscopy. In La0.6Ce0.4NiO3 catalyst, the substitution of Ni by 0.1% Zr results in a constant high catalytic activity (83% hydrogen yield at 800°C) due to the presence of reducible “NiO‐species interacted strongly with the support” (stable metallic Ni over reduced catalyst) and redox input by ceria phase for laying instant lattice oxygen during lag‐off period of CO2. Substitution of Ni by Zr and Y in the CeNiO3 catalyst system nurtures Ni3Y (providing highly stable metallic Ni for CH4 decomposition) and cerium yttrium oxide phases (providing strong redox input). CeNi0.9Zr0.01Y0.09O...

Catalysts

Samarium oxide (Sm2O3) is a versatile surface for CO2 and H2 interaction and conversion. Samarium... more Samarium oxide (Sm2O3) is a versatile surface for CO2 and H2 interaction and conversion. Samarium oxide-supported Ni, samarium oxide-supported Co-Ni, and samarium oxide-supported Ru-Ni catalysts were tested for CO2 methanation and were characterized by X-ray diffraction, nitrogen physisorption, infrared spectroscopy, H2-temperature programmed reduction, and X-ray photoelectron spectroscopy. Limited H2 dissociation and widely available surface carbonate and formate species over 20 wt.% Ni, dispersed over Sm2O3, resulted in ~98% CH4 selectivity. The low selectivity for CO could be due to the reforming reaction between CH4 (methanation product) and CO2. Co-impregnation of cobalt with nickel over Sm2O3 had high surface adsorbed oxygen and higher CO selectivity. On the other hand, co-impregnation of ruthenium and nickel over Sm2O3 led to more than one catalytic active site, carbonate species, lack of formate species, and 94% CH4 selectivity. It indicated the following route of CH4 synthe...

ACS Omega

Developing cost-effective nonprecious active metal-based catalysts for syngas (H 2 /CO) productio... more Developing cost-effective nonprecious active metal-based catalysts for syngas (H 2 /CO) production via the dry reforming of methane (DRM) for industrial applications has remained a challenge. Herein, we utilized a facile and scalable mechanochemical method to develop Bapromoted (1−5 wt %) zirconia and yttria−zirconia-supported Ni-based DRM catalysts. BET surface area and porosity measurements, infrared, ultraviolet−visible, and Raman spectroscopy, transmission electron microscopy, and temperature-programmed cyclic (reduction−oxidation− reduction) experiments were performed to characterize and elucidate the catalytic performance of the synthesized materials. Among different catalysts tested, the inferior catalytic performance of 5Ni/Zr was attributed to the unstable monoclinic ZrO 2 support and weakly interacting NiO species whereas the 5Ni/YZr system performed better because of the stable cubic ZrO 2 phase and stronger metal−support interaction. It is established that the addition of Ba to the catalysts improves the oxygen-endowing capacity and stabilization of the cubic ZrO 2 and BaZrO 3 phases. Among the Ba-promoted catalysts, owing to the optimal active metal particle size and excess ionic CO 3 2− species, the 5Ni4Ba/YZr catalyst demonstrated a high, stable H 2 yield (i.e., 79% with a 0.94 H 2 /CO ratio) for up to 7 h of time on stream. The 5Ni4Ba/YZr catalyst had the highest H 2 formation rate, 1.14 mol g −1 h −1 and lowest apparent activation energy, 20.07 kJ/mol, among all zirconia-supported Ni catalyst systems.

The Role of Strontium as an Economic Promoter Over WO3 + ZrO2 Supported Ni Catalyst for H2 Production Through Dry Reforming of Methane

Catalysis Letters

Promoted Yttria-Zirconia Supported Ni Catalyst for Syngas Production Through Dry Reforming of Methane

Iron-promoted zirconia-alumina supported Ni catalyst for highly efficient and cost-effective hydrogen production via dry reforming of methane

Journal of Environmental Sciences

COx -free H2 Production via Catalytic Decomposition of CH4 over Fe Supported on Tungsten oxide-activated Carbon Catalyst: Effect of Tungsten Loading

Arabian Journal of Chemistry

Syngas production from methane dry reforming via optimization of tungsten trioxide-promoted mesoporous γ-alumina supported nickel catalyst

International Journal of Hydrogen Energy

Holmium promoted yttria-zirconia supported Ni catalyst for H2 production via dry reforming of methane

International Journal of Hydrogen Energy

A highly active and cost-effective tungsten modified Ni-based catalyst for the production of hydrogen via methane dry reforming

Catalysis Communications

Cost Effective Wo3-Γ-Al2o3 Supported Nickel Catalyst System for Hydrogen Gas Production Through Dry Reforming of Methane

SSRN Electronic Journal

Promotional effect of addition of ceria over yttria-zirconia supported Ni based catalyst system for hydrogen production through dry reforming of methane

International Journal of Hydrogen Energy

Energy Science & Engineering, 2022

Role of Ca, Cr, Ga and Gd promotor over lanthanazirconia-supported Ni catalyst towards H2-rich sy... more Role of Ca, Cr, Ga and Gd promotor over lanthanazirconia-supported Ni catalyst towards H2-rich syngas production through dry reforming of methane. Energy Science & Engineering.

Recycling calcium oxide nanoparticles for sustainable biodiesel production from nonedible feedstock Argemone mexicana L

Biofuels

Scientific Reports, Jul 12, 2023

Biomass waste streams are a possible feedstock for a range of eco-friendly products and a crucial... more Biomass waste streams are a possible feedstock for a range of eco-friendly products and a crucial alternative energy source for achieving carbon neutrality; therefore, the efficient management of biomass waste has taken on a greater significance in recent years. Due to its well-comparable physicchemical properties with fossil diesel, biodiesel is a potential substitute for fossil fuel. This study aimed to synthesize biodiesel from the widely available non-edible seed oil of Sisymbrium irio L. (a member of the Brassicaceae family) via a transesterification procedure over a homemade TiO 2 catalyst. At 1:16 oil to methanol ratio, 93% biodiesel yield was obtained over 20 mg catalyst at 60 °C and 60 min. The ASTM methods were used to analyze the fuel properties. The quantitative and qualitative analysis was performed by FT-IR, GC-MS, and NMR spectroscopy. GC-MS study confirms 16 different types of fatty acids of methyl esters. FT-IR analysis showed important peaks that confirm the successful occurrence of biodiesel. 1 H-NMR and 13 C-NMR showed important peaks for converting triglycerides into corresponding FAMEs. The acid value (0.42 mg KOH/mg/kg), flash point (106 °C), and water content (0.034) of biodiesel are below the specified limit of ASTM D6751 whereas kinetic viscosity (3.72 mm 2 /s), density (0.874 kg/L), cloud point (− 4.3 °C) and pour point (− 9.6 °C) and high heating value (41.62 MJ/kg) fall within the specified range of ASTM D6751 test limit. The Unsaturation degree and oxidative stability of biodiesel are above ASTM D6751 test limit. The physic-chemical properties of the SIB confirm that it is eco-friendly fuel and a competitive source for manufacturing biodiesel on a commercial scale. Furthermore, the SIB is engine friendly and has good fuel efficacy. Abbreviations SIB Sisymbrium irio Biodiesel TiO 2 Titanium dioxide FFA Free fatty acid SEM Scanning electron microscopy XRD X-rays diffraction H and C-NMR Nuclear magnetic resonance GC-MS Gas chromatography mass spectrometry FT-IR spectroscopy Fourier transform infrared spectroscopy ASTM

Reforming of methane: Effects of active metals, supports, and promoters

Catalysis Reviews-science and Engineering, May 27, 2023

Enhanced direct methanation of CO2 using Ni-based catalysts supported on ZrO2, CeO2-ZrO2, and La2O3-ZrO2: The effect of support material on the reducible NiO-interacted species and catalytic activity

Molecular Catalysis

Rh promoted Ni over yttria–zirconia supported catalyst for hydrogen‐rich syngas production through dry reforming of methane

Energy Science & Engineering

Rh‐promoted YZr‐supported Ni catalyst (5Ni/YZr) is investigated for DRM and characterized with X‐... more Rh‐promoted YZr‐supported Ni catalyst (5Ni/YZr) is investigated for DRM and characterized with X‐ray diffraction, Raman, infrared spectroscopy, cyclic reduction–oxidation–reduction temperature programmed experiment, thermogravimetry, and transmission electron microscope. Over 5Ni/YZr, some active sites become inactive under the CO2 stream and limit H2 yield to ∼71%. Upon 4 wt% Rh addition over 5Ni/YZr; more than one type of stable active sites (Rh and Ni) generates, moderate basic sites are enhanced, wide ranges of CO2‐interacted surface species (especially bidentate CO2‐adsorbed species) are grown and graphitic carbon proportion over spent catalyst declines. Thisresulted in 87.35% H2 yield and 86.73% CO yield up to 420 min. 5Ni4Rh/YZr catalyst maintains ∼80% H2 yield at the end of 27 h of DRM reaction.

International Journal of Chemical Engineering

A better understanding of the reaction mechanism and kinetics of dry reforming of methane (DRM) r... more A better understanding of the reaction mechanism and kinetics of dry reforming of methane (DRM) remains challenging, necessitating additional research to develop robust catalytic systems with high catalytic performance, low cost, and high stability. Herein, we prepared a zirconia-alumina-supported Ni-Fe catalyst and used it for DRM. Different partial pressures and temperatures are used to test the dry reforming of methane reaction as a detailed kinetic study. The optimal reaction conditions for DRM catalysis are 800°C reaction temperature, 43.42 kPa CO2 partial pressure, and 57.9 kPa CH4 partial pressure. At these optimal reaction conditions, the catalyst shows a 0.436 kPa2 equilibrium constant, a 0.7725  m o l C H 4 /gCat/h rate of CH4 consumption, a 0.00651  m o l C H 4 /m2/h arial rate of CH4 consumption, a 1.6515  m o l H 2 /gCat/h rate of H2 formation, a 1.4386 molCO/gCat/h rate of CO formation. This study’s findings will inspire the cost-effective production of robust catalyti...

Promoted Yttria-Zirconia Supported Ni Catalyst for Syngas Production Through Dry Reforming of Methane

The influence of Ni stability, redox, and lattice oxygen capacity on catalytic hydrogen production via methane dry reforming in innovative metal oxide systems

Energy Science & Engineering

Finding a robust catalytic system for hydrogen production via dry reforming of methane (DRM) rema... more Finding a robust catalytic system for hydrogen production via dry reforming of methane (DRM) remains a challenge. Herein, MNi0.9Zr1−xYxO3 (M = Ce, La, and La0.6Ce0.4; x = 0.00, 0.05, 0.07, and 0.09) catalyst was prepared by the sol–gel method, tested for DRM and characterized by surface area and porosity, X‐ray diffraction, H2‐temperature programmed reduction, thermogravimetry, and transmission electron microscopy. In La0.6Ce0.4NiO3 catalyst, the substitution of Ni by 0.1% Zr results in a constant high catalytic activity (83% hydrogen yield at 800°C) due to the presence of reducible “NiO‐species interacted strongly with the support” (stable metallic Ni over reduced catalyst) and redox input by ceria phase for laying instant lattice oxygen during lag‐off period of CO2. Substitution of Ni by Zr and Y in the CeNiO3 catalyst system nurtures Ni3Y (providing highly stable metallic Ni for CH4 decomposition) and cerium yttrium oxide phases (providing strong redox input). CeNi0.9Zr0.01Y0.09O...

Catalysts

Samarium oxide (Sm2O3) is a versatile surface for CO2 and H2 interaction and conversion. Samarium... more Samarium oxide (Sm2O3) is a versatile surface for CO2 and H2 interaction and conversion. Samarium oxide-supported Ni, samarium oxide-supported Co-Ni, and samarium oxide-supported Ru-Ni catalysts were tested for CO2 methanation and were characterized by X-ray diffraction, nitrogen physisorption, infrared spectroscopy, H2-temperature programmed reduction, and X-ray photoelectron spectroscopy. Limited H2 dissociation and widely available surface carbonate and formate species over 20 wt.% Ni, dispersed over Sm2O3, resulted in ~98% CH4 selectivity. The low selectivity for CO could be due to the reforming reaction between CH4 (methanation product) and CO2. Co-impregnation of cobalt with nickel over Sm2O3 had high surface adsorbed oxygen and higher CO selectivity. On the other hand, co-impregnation of ruthenium and nickel over Sm2O3 led to more than one catalytic active site, carbonate species, lack of formate species, and 94% CH4 selectivity. It indicated the following route of CH4 synthe...

ACS Omega

Developing cost-effective nonprecious active metal-based catalysts for syngas (H 2 /CO) productio... more Developing cost-effective nonprecious active metal-based catalysts for syngas (H 2 /CO) production via the dry reforming of methane (DRM) for industrial applications has remained a challenge. Herein, we utilized a facile and scalable mechanochemical method to develop Bapromoted (1−5 wt %) zirconia and yttria−zirconia-supported Ni-based DRM catalysts. BET surface area and porosity measurements, infrared, ultraviolet−visible, and Raman spectroscopy, transmission electron microscopy, and temperature-programmed cyclic (reduction−oxidation− reduction) experiments were performed to characterize and elucidate the catalytic performance of the synthesized materials. Among different catalysts tested, the inferior catalytic performance of 5Ni/Zr was attributed to the unstable monoclinic ZrO 2 support and weakly interacting NiO species whereas the 5Ni/YZr system performed better because of the stable cubic ZrO 2 phase and stronger metal−support interaction. It is established that the addition of Ba to the catalysts improves the oxygen-endowing capacity and stabilization of the cubic ZrO 2 and BaZrO 3 phases. Among the Ba-promoted catalysts, owing to the optimal active metal particle size and excess ionic CO 3 2− species, the 5Ni4Ba/YZr catalyst demonstrated a high, stable H 2 yield (i.e., 79% with a 0.94 H 2 /CO ratio) for up to 7 h of time on stream. The 5Ni4Ba/YZr catalyst had the highest H 2 formation rate, 1.14 mol g −1 h −1 and lowest apparent activation energy, 20.07 kJ/mol, among all zirconia-supported Ni catalyst systems.

The Role of Strontium as an Economic Promoter Over WO3 + ZrO2 Supported Ni Catalyst for H2 Production Through Dry Reforming of Methane

Catalysis Letters

Promoted Yttria-Zirconia Supported Ni Catalyst for Syngas Production Through Dry Reforming of Methane

Iron-promoted zirconia-alumina supported Ni catalyst for highly efficient and cost-effective hydrogen production via dry reforming of methane

Journal of Environmental Sciences

COx -free H2 Production via Catalytic Decomposition of CH4 over Fe Supported on Tungsten oxide-activated Carbon Catalyst: Effect of Tungsten Loading

Arabian Journal of Chemistry

Syngas production from methane dry reforming via optimization of tungsten trioxide-promoted mesoporous γ-alumina supported nickel catalyst

International Journal of Hydrogen Energy

Holmium promoted yttria-zirconia supported Ni catalyst for H2 production via dry reforming of methane

International Journal of Hydrogen Energy

A highly active and cost-effective tungsten modified Ni-based catalyst for the production of hydrogen via methane dry reforming

Catalysis Communications

Cost Effective Wo3-Γ-Al2o3 Supported Nickel Catalyst System for Hydrogen Gas Production Through Dry Reforming of Methane

SSRN Electronic Journal

Promotional effect of addition of ceria over yttria-zirconia supported Ni based catalyst system for hydrogen production through dry reforming of methane

International Journal of Hydrogen Energy

Energy Science & Engineering, 2022

Role of Ca, Cr, Ga and Gd promotor over lanthanazirconia-supported Ni catalyst towards H2-rich sy... more Role of Ca, Cr, Ga and Gd promotor over lanthanazirconia-supported Ni catalyst towards H2-rich syngas production through dry reforming of methane. Energy Science & Engineering.