33 results on '"Bahruji H"'
Search Results
2. Novel Fabrication of Photoactive CuO/HY Zeolite as an Efficient Catalyst for Photodecolorization of Malachite Green
- Author
-
Hassan, N. S., Jalil, A. A., Satar, M. A. H., Hitam, C. N. C., Aziz, F. F. A., Fauzi, A. A., Aziz, M. A. A., and Bahruji, H.
- Published
- 2020
- Full Text
- View/download PDF
3. Hydrogen production by photoreforming of biofuels using Au, Pd and Au–Pd/TiO2 photocatalysts
- Author
-
Bowker, M., Morton, C., Kennedy, J., Bahruji, H., Greves, J., Jones, W., Davies, P.R., Brookes, C., Wells, P.P., and Dimitratos, N.
- Published
- 2014
- Full Text
- View/download PDF
4. Rutile TiO2–Pd Photocatalysts for Hydrogen Gas Production from Methanol Reforming
- Author
-
Bahruji, H., Bowker, M., Davies, P. R., Morgan, D. J., Morton, C. A., Egerton, T. A., Kennedy, J., and Jones, Wilm
- Published
- 2015
- Full Text
- View/download PDF
5. Crystalline C3N4/CeO2 composites as photocatalyst for hydrogen production in visible light.
- Author
-
Saman, F, Bahruji, H, and Mahadi, H
- Published
- 2022
- Full Text
- View/download PDF
6. Condensation of Indole with Isatin over AlCl3/Mesoporous Aluminosilicate
- Author
-
Purbaningtias, T. E., Didik Prasetyoko, Bahruji, H., Zein, Y. M., Triwahyono, S., Fadlan, A., and Qoniah, I.
- Subjects
condensation ,Chemistry ,AlCl3 ,mesoporous aluminosilicate ,indole ,impregnation ,isatin ,QD1-999 - Abstract
Aluminium chloride immobilized on mesoporous aluminosilicate was investigated as catalysts in the condensation of isatin with indole. AlCl3/mesoporous aluminosilicate (AlCl3/AM) catalysts were prepared by impregnation of 1, 5, 10 and 15 wt% AlCl3 on the surface of mesoporous aluminosilicate. A maximum conversion of isatin was achieved using 15% AlCl3/AM catalyst whereas the highest selectivity of 68.97% towards trisindoline was obtained using pure AM. The activity of the catalysts was depended on their acid site number and surface area. The number of Brønsted acid and the surface area affected to the conversion of isatin while the total acidity and the number of Lewis acid influenced the selectivity.
- Published
- 2015
7. PdZn catalysts for CO2 hydrogenation to methanol using chemical vapour impregnation (CVI).
- Author
-
Bahruji, H., Hayward, J., Ruiz Esquius, J., Morgan, D. J., Hutchings, G. J., Bowker, M., and Jones, W.
- Abstract
The formation of PdZn bimetallic alloys on ZnO, TiO
2 and Al2 O3 supports was investigated, together with the effect of alloy formation on the CO2 hydrogenation reaction. The chemical vapour impregnation (CVI) method produced PdZn nanoparticles with diameters of 3–6 nm. X-ray photoelectron spectroscopy and X-ray diffraction revealed the changes in the structure of the PdZn alloy that help stabilise formate intermediates during methanol synthesis. PdZn supported on TiO2 exhibits high methanol productivity of 1730 mmol kgcat −1 h−1 that is associated with the high dispersion of the supported PdZn alloy. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
8. Hydrogen production by photoreforming of biofuels using Au, Pd and Au–Pd/TiO2 photocatalysts.
- Author
-
Bowker, M., Morton, C., Kennedy, J., Bahruji, H., Greves, J., Jones, W., Davies, P.R., Brookes, C., Wells, P.P., and Dimitratos, N.
- Subjects
- *
HYDROGEN production , *BIOMASS energy , *PHOTOCATALYSTS , *METAL catalysts , *CATALYTIC activity , *TITANIUM dioxide - Abstract
Highlights: [•] Au catalysts are shown to be active for photocatalytic reforming of a variety of alcohols. [•] Au is less active than Pd. [•] Au–Pd alloys appear to be a little more active than either individual component. [•] There is a maximum in activity at low loadings, and high loadings lead to much diminished activity. [•] Incipient wetness impregnation appears to be a good method for the preparation of such catalysts. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
9. Hydrogen production by photoreforming of biofuels using Au, Pd and Au-Pd/TiO2 photocatalysts
- Author
-
Catherine Brookes, Hasliza Bahruji, J. Greves, Nikolaos Dimitratos, Clare Ann Morton, Philip Rosser Davies, Wilm Jones, Peter P. Wells, Julia Kennedy, Michael Bowker, Bowker, M., Morton, C., Kennedy, J., Bahruji, H., Greves, J., Jones, W., Davies, P.R., Brookes, C., Wells, P.P., and Dimitratos, N.
- Subjects
Alkane ,chemistry.chemical_classification ,Hydrogen ,Pd catalyst ,chemistry.chemical_element ,Photoreforming ,Catalysis ,Au catalyst ,Catalysi ,Metal ,Solar fuel ,Colloid ,chemistry ,Chemical engineering ,Biofuel ,visual_art ,visual_art.visual_art_medium ,Hydrogen production ,Organic chemistry ,Physical and Theoretical Chemistry ,Alcohol ,Oxygenate - Abstract
We have prepared a variety of Au, Pd and Au-Pd catalysts loaded onto P25 titania to determine how effective these materials are for the anaerobic, ambient temperature reforming of alcohols with water to produce hydrogen, and to examine the effect of the preparation method on their performance. Catalysts produced by both incipient wetness (IW) methods and by colloidal methods are successful materials for producing hydrogen, with the IW catalysts proving to be the best for the same metal loading. It is shown that, although gold catalysts generally have lower hydrogen yield than for Pd, alloying Au with Pd gives more active materials than either alone at the same weight loading, due to a synergistic effect. The catalysts are active for reforming a range of alcohols, generally producing CO2, H2 and an alkane. However, it is essential for good activity to have an H at the a-position to the oxygenate function, and so, carboxylic acids and ketones do not work. These catalysts generally show a maximum in activity at low loadings of metal (∼0.5 wt%) due to a requirement for maximising the active interface between the metal nanoparticles and the photo-active titania. © 2013 Elsevier Inc. All rights reserved.
- Published
- 2014
10. Coprecipitation and hydrothermal synthesis of CaO from dolomite in the presence of Sapindus rarak extract for biodiesel production: catalysts characterization and optimization.
- Author
-
Widiarti N, Holilah H, Bahruji H, Nugraha RE, Suprapto S, Ni'mah YL, and Prasetyoko D
- Abstract
High-purity CaO cubic crystallites extracted from limestone exhibited excellent activity as base catalysts for waste cooking oil (WCO) conversion into biodiesel. Saponin from Sapindus rarak extract acted as a surfactant in CaO extraction and transformation into well-defined cubic microcrystallites. The application of saponin from Sapindus rarak extract as a surfactant for CaO production results in a high level of CaO purity and particle size reduction compared to directly calcined limestone (CaO-MgO). The catalytic activity was evaluated on CaO from hydrothermal and co-precipitation synthesis, MgO and CaO-MgO derived from limestone, giving hydrothermal CaO catalysts enhanced biodiesel yield. Optimization of transesterification conditions using Box Behnken Design response surface methodology achieved 92.40% biodiesel yield at 65 °C, 3 h reaction time and when using 5% of CaO catalysts., Competing Interests: There are no reported financial or personal conflicts of interest by the authors of this study., (This journal is © The Royal Society of Chemistry.)
- Published
- 2024
- Full Text
- View/download PDF
11. Microwave-assisted synthesis of silver nanoparticles as a colorimetric sensor for hydrogen peroxide.
- Author
-
Ismillayli N, Suprapto S, Santoso E, Nugraha RE, Holilah H, Bahruji H, Jalil AA, Hermanto D, and Prasetyoko D
- Abstract
To consider silver nanoparticles (AgNPs) as a colorimetric sensor for H
2 O2 we require investigation of the effects of the homogeneity of the nanoparticle size and morphology on the sensor parameters. Uniformly-sized Ag nanoparticles with diameters of ∼18.8 ± 2.8 nm were produced using microwave irradiation (AgNP1) but non-uniform particles with diameters of ∼71.2 ± 19.4 nm (AgNP2) were formed without microwave irradiation. Microwave synthesis produced AgNP1 with superiority in terms of repeatability, selectivity and sensor stability for up to eight months of storage over AgNP2. AgNP1 exhibited higher sensitivity and detection limits in the working range of 0.01-40000 μM as compared to AgNP2. The application of the AgNP sensor to milk samples provided recovery values of 99.09-100.56% for AgNP1 and 98.18-101.90% for AgNP2. Microwave irradiation resulted in strong and uniform PVP-Ag interactions for isotropic growth into small nanoparticles. Size and morphology uniformity determined the characteristics of the AgNP sensor that can be applied for H2 O2 detection in a wide range of concentrations and real-time evaluation, with the potential for industrial applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2024
- Full Text
- View/download PDF
12. The role of pH-induced tautomerism of polyvinylpyrrolidone on the size, stability, and antioxidant and antibacterial activities of silver nanoparticles synthesized using microwave radiation.
- Author
-
Ismillayli N, Suprapto S, Santoso E, Nugraha RE, Holilah H, Bahruji H, Jalil AA, Hermanto D, and Prasetyoko D
- Abstract
Tautomerism alters the structure and properties of materials, which can be exploited to control their chemical and biological activities. The role of pH-induced tautomerism of polyvinylpyrrolidone (PVP) was determined by measuring the size, stability, and antioxidant and antibacterial properties of microwave synthesized-silver nanoparticles (AgNPs). TEM and XRD analyses confirmed the formation of face-centered cubic silver nanoparticles. PVP stabilized the AgNPs by interaction with the carbonyl or hydroxyl groups depending on the tautomerization under different pH conditions. At pH 4, PVP was stable in the keto tautomer, stabilizing Ag through electron donation of oxygen atoms in the carbonyl group, producing smaller AgNPs with a higher zeta potential. At pH 7 and 9, the enol tautomer PVP stabilized the AgNPs via oxygen atoms in the hydroxyl group, forming large nanoparticles. The keto form of PVP improved the stability and antioxidant and antibacterial properties of AgNPs compared with the enol form. This study also excluded the antioxidant contribution of PVP via hydrogen donation to free radicals. A facile method for controlling the size of AgNPs by adapting the pH-induced tautomerism of PVP that affects their stability and antioxidant and antibacterial activities is thus reported., Competing Interests: The authors declare that there is no conflict of interest., (This journal is © The Royal Society of Chemistry.)
- Published
- 2024
- Full Text
- View/download PDF
13. Synthesis of mesoporous zeolite Y using Sapindus rarak extract as natural organic surfactant for deoxygenation of Reutealis trisperma oil to biofuel.
- Author
-
Aziz A, Andini Putri BG, Prasetyoko D, Nugraha RE, Holilah H, Bahruji H, Jalil AA, Suprapto S, Hartati H, and Asikin-Mijan N
- Abstract
Saponin is a plant-derived chemical with an amphiphilic glycoconjugate structure extracted from sapindaceae plants like Sapindus rarak . This study investigated saponin extract of Sapindus rarak as a natural template for formation of mesoporous zeolite Y. Surface area and mesoporosity of zeolite Y were improved with optimization of Sapindus rarak extract (SRE) concentration (Y-Ln; n = 2, 5, 10 or 15 mL), reaching 216.26 m
2 mesoporous area and 0.214 cm3 g-1 mesoporous volume for Y-L10 samples. A different loading of Ni was impregnated onto Y-L10 zeolite to improve Lewis/Brønsted acidity as catalysts in the deoxygenation of Reutealis trisperma oil (RTO) into hydrocarbon fuels. Impregnating 15% Ni on NaY zeolite enhanced Lewis acidity to 0.4556 mmol g-1 , producing 48.8% liquid oil with 85.43% degree of deoxygenation. A high selectivity towards C15 and C17 hydrocarbon was analyzed from liquid yield, indicating the contributing factor from Lewis acidity and mesoporosity to enhance deoxygenation and prevent the hydrocracking reaction., Competing Interests: There are no reported financial or personal conflicts of interest by the authors of this study., (This journal is © The Royal Society of Chemistry.)- Published
- 2023
- Full Text
- View/download PDF
14. Direct synthesis of Fe-aluminosilicates from red mud for catalytic deoxygenation of waste cooking oil.
- Author
-
Ramdhani EP, Santoso E, Holilah H, Nugraha RE, Bahruji H, Suprapto S, Jalil AA, Asikin-Mijan N, Akhlus S, and Prasetyoko D
- Abstract
Conversion of red mud (RM) that contains a high level of silica, alumina and iron minerals into heterogenous catalysts, offers a route for the utilization of abundant toxic by-products of bauxite refining. In this study, the conversion of red mud into mesoporous Fe-aluminosilicate produced selective catalysts for the deoxygenation of waste cooking oil to green diesel hydrocarbons. Direct conversion of red mud in the presence cetyltrimethylammonium bromide into Fe-aluminosilicate (RM-CTA) produced a highly mesoporous structure with oligomeric Fe
2 O3 clusters within the pores. When red mud was treated with citric acid (RM-CA-CTA), a wide distribution of Fe2 O3 particles was obtained on the aluminosilicate external surface. TEM analysis showed a well-defined hexagonal mesoporosity of Fe-aluminosilicate obtained from untreated red mud, while the treated red mud produced lower regularity mesopores. RM-CTA exhibits 60% WCO conversion and 83.72% selectivity towards liquid products with 80.44% diesel hydrocarbon (C11 -C18 ) yield. The high selectivity was due to the high acidity of Fe-aluminosilicate to dissociate the C-O bond and the regularity of mesostructure for efficient hydrocarbon diffusion, preventing a cracking reaction., Competing Interests: There are no reported financial or personal conflicts of interest by the authors of this study., (This journal is © The Royal Society of Chemistry.)- Published
- 2023
- Full Text
- View/download PDF
15. Optimization of hierarchical ZSM-5 structure from kaolin as catalysts for biofuel production.
- Author
-
Maharani DK, Kusumawati Y, Safitri WN, Nugraha RE, Holilah H, Sholeha NA, Jalil AA, Bahruji H, and Prasetyoko D
- Abstract
Optimization of hierarchical ZSM-5 structure by variation of the first hydrothermal step at different times provides insight into the evolution of micro/mesopores and its effect as a catalyst for deoxygenation reaction. The degree of tetrapropylammonium hydroxide (TPAOH) incorporation as an MFI structure directing agent and N -cetyl- N , N , N -trimethylammonium bromide (CTAB) as a mesoporogen was monitored to understand the effect towards pore formation. Amorphous aluminosilicate without the framework-bound TPAOH achieved within 1.5 h of hydrothermal treatment provides flexibility to incorporate CTAB for forming well-defined mesoporous structures. Further incorporation of TPAOH within the restrained ZSM-5 framework reduces the flexibility of aluminosilicate gel to interact with CTAB to form mesopores. The optimized hierarchical ZSM-5 was obtained by allowing hydrothermal condensation at 3 h, in which the synergy between the readily formed ZSM-5 crystallites and the amorphous aluminosilicate generates the proximity between micropores and mesopores. A high acidity and micro/mesoporous synergy obtained after 3 h exhibit 71.6% diesel hydrocarbon selectivity because of the improved diffusion of reactant within the hierarchical structures., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)
- Published
- 2023
- Full Text
- View/download PDF
16. Hydrothermal effect of gunningite use Pluronic F127-Gelatin as template and the ibuprofen adsorption performance.
- Author
-
Ulfa M, Iswanti Y, Irwanti Y, Sholeha NA, Masruchin N, Subagyo R, Bahruji H, and Prasetyoko D
- Abstract
The gunningite has been successfully synthesized using Pluronic F127 and gelatin as template via hydrothermal at 100-200 °C for 12-48 h. By scanning electron microscopy, nitrogen adsorption-desorption, and X-ray diffraction, changes in structure, pore size, and morphology due to ibuprofen adsorption were investigated in gunningite. Various hydrothermal (temperature and time) parameters had an influence on the percentage elimination (%) of ibuprofens. Gunningite's specific surface area intensifies from 14.60 to 24.03 m
2 /g as the longer hydrothermal time. In batch adsorption studies, the resulting sample was conducted to isotherm and kinetic analysis to evaluate the distribution of ibuprofen between the liquid and solid phases. Pseudo-first-order kinetics with an adsorption capacity range of 27-34.5 mg g-1 were the best fit for the observed data. Consequently, gunningite may be considered a viable adsorbent for the large-scale treatment of water contaminated with ibuprofen and related anti-inflammatory medicines., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors.)- Published
- 2023
- Full Text
- View/download PDF
17. Hectorite-CTAB-alginate composite beads for water treatment: kinetic, isothermal and thermodynamic studies.
- Author
-
Asranudin, Holilah, Purnomo AS, Bahruji H, Allouss D, El Alaoui-Elbalrhiti I, Subagyo R, Rohmah AA, and Prasetyoko D
- Abstract
Encapsulation of hectorite-modified CTAB with Ca-alginate formed reusable adsorbent beads for wastewater treatment. The thermogravimetric analysis (TGA) investigation indicated excellent thermal stability results for BHec-40 compared to Hec-40. Although the mesoporous surface area of BHec-40 decreased to 79.74 m
2 g-1 compared to 224.21 m2 g-1 for Hec-40, the hectorite-CTAB-alginate beads showed high adsorption capacity and stability for methyl orange (MO) adsorption with more than 60% removal after five adsorption-desorption cycles. The influence of pH (3-11), temperature (30, 40, and 50 °C), initial concentration (50-400 mg L-1 ), and contact time were studied to obtain the kinetics and thermodynamics of adsorption. The outcomes revealed a maximum monolayer adsorption capacity of 117.71 mg g-1 for BHec-40. The kinetics of adsorption demonstrated the suitability of using the pseudo-first-order kinetic model, while the equilibrium adsorption data follows the Langmuir isotherm. Thermodynamic analysis indicates physisorption of MO onto BHec-40. BHec-40 improves the reusability as an adsorbent for the removal of anionic dyes from aqueous media., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2023
- Full Text
- View/download PDF
18. The effect of gelatin as pore expander in green synthesis mesoporous silica for methylene blue adsorption.
- Author
-
Ulfa M, Prasetyoko D, Trisunaryanti W, Bahruji H, Fadila ZA, and Sholeha NA
- Subjects
- Adsorption, Gelatin, Porosity, Methylene Blue, Silicon Dioxide chemistry
- Abstract
Mesoporous silica NSG had been synthesized while employing gelatin as a natural template to successfully increase the particle size and expand the pore diameter of NSG. All silica samples exhibited a similar XRD pattern with a broad peak centred at 2θ = 22.9°, as the characteristic of amorphous silica. FTIR results showed that the reduction of Si-O-Si symmetric stretching vibrations at 1075 cm
-1 was due to the use of a high percentage of gelatin. Moreover, TEM analysis displayed the mesoporous channels in the form of a honeycomb structure with a diameter of ± 6 nm. Gelatin enhanced the surface area of silica from 467 to 510 m2 /g, the pore volume from 0.64 to 0.72 cc/g and expanded the pore diameter from 3.5 nm to 6.0 nm. The expansion of the ordered mesopores with the increase of P123: gelatin ratios was elucidated by the pore size distribution. The adsorption capacity of methylene blue (MB) was improved on mesoporous silica with an expanded pore dimension to give 168 mg/g adsorption capacity within 70 min., (© 2022. The Author(s).)- Published
- 2022
- Full Text
- View/download PDF
19. Fast Removal of Methylene Blue via Adsorption-Photodegradation on TiO 2 /SBA-15 Synthesized by Slow Calcination.
- Author
-
Ulfa M, Al Afif H, Saraswati TE, and Bahruji H
- Abstract
TiO
2 /SBA-15 photocatalysts were successfully prepared by impregnating low loading titania to SBA-15 via slow calcination. The photocatalyst is efficient for fast methylene blue removal via adsorption and photodegradation methods. The impregnation of low TiO2 loading via slow calcination enhanced TiO2 dispersion that preserved the SBA-15 porosity and uniform morphology. High interfacial interaction of TiO2 /SBA-15 improves TiO2 photoresponse by narrowing the bandgap, resulting in a stronger redox ability. The methylene blue removal on 10%TiO2 /SBA-15 followed the pseudo-second-order kinetic model that reached 67% removal efficiency in 90 min. The synergy between adsorption and photodegradation is responsible for the fast methylene blue removal. These results indicate the importance of maintaining the adsorption capacity in SBA-15 after impregnation with TiO2 for efficient adsorption-photodegradation processes, which can be achieved by controlling the deposition of TiO2 on SBA-15. A low titania loading further reduced the cost of photocatalysts, thus becoming a potential material for environmental pollution treatment.- Published
- 2022
- Full Text
- View/download PDF
20. Uniform rod and spherical nanocrystalline celluloses from hydrolysis of industrial pepper waste (Piper nigrum L.) using organic acid and inorganic acid.
- Author
-
Holilah H, Bahruji H, Ediati R, Asranudin A, Jalil AA, Piluharto B, Nugraha RE, and Prasetyoko D
- Subjects
- Cellulose chemistry, Hydrolysis, Particle Size, Industrial Waste, Piper nigrum
- Abstract
Conversion of lignocellulosic biowastes from agricultural industry into nanocrystalline cellulose provides pathway to reduce environmental pollution while enhancing the economic value of biowastes. Nanocellulose (NCC) with uniform morphology was isolated from pepper (Piper nigrum L.) stalk waste (PW) using acid hydrolysis method. The role of inorganic acids (sulfuric acid, hydrochloric acid, phosphoric acid), organic acids (oxalic acid, citric acid, acetic acid) and variation of sonication times were investigated on the physicochemical characteristics, self-assembled structure, crystallinity, particle size, zeta potential and thermal stability of the isolated nanocellulose. Hydrolysis using inorganic acids transformed cellulose from PW into a spherical shaped NCC at ~33-67 nm of average diameter. Meanwhile hydrolysis in organic acids produced rod-shaped NCC at 210-321 nm in length. This study highlighted the role of acidity strength for organic acid and inorganic acid in controlling the level of hydrogen bond dissociation and the dissolution of amorphous fragments, which consequently directing the morphology and the physicochemical properties of NCCs., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
21. Controlling the Size and Porosity of Sodalite Nanoparticles from Indonesian Kaolin for Pb 2+ Removal.
- Author
-
Ulfa M, Masykur A, Nofitasari AF, Sholeha NA, Suprapto S, Bahruji H, and Prasetyoko D
- Abstract
Mesoporous sodalite nanoparticles were directly synthesized from Indonesian kaolin with the addition of CTABr as a mesopore template. The studies highlighted the importance of aging time (3-12 h) and temperature (50-80 °C) on increasing surface area and mesoporosity of sodalite. Indonesian kaolin was used without pre-treatment and transformed to sodalite following the initial molar composition of 10 Na
2 O: 2 SiO2 : Al2 O3 : 128 H2 O. Characterization data revealed the formation of high surface area sodalite with mesoporosity at increasing aging temperatures and times. The presence of CTABr as templates produced sodalites nanoparticles with smaller aggregates than the non-template sodalite. The sodalite sample obtained at 80 °C of crystallization temperature for 9 h (S80H9) displayed the highest mesopore volume (0.07612 cm3 /g) and the highest adsorption capacity of Pb2+ (212.24 mg/g). Pb2+ was suggested to adsorb via ion exchange with the Na+ counter cation and physical adsorption.- Published
- 2022
- Full Text
- View/download PDF
22. Green Synthesis of Hexagonal Hematite (α-Fe 2 O 3 ) Flakes Using Pluronic F127-Gelatin Template for Adsorption and Photodegradation of Ibuprofen.
- Author
-
Ulfa M, Prasetyoko D, Bahruji H, and Nugraha RE
- Abstract
Hematite (α-Fe
2 O3 ) with uniform hexagonal flake morphology has been successfully synthesized using a combination of gelatin as natural template with F127 via hydrothermal method. The resulting hematite was investigated as adsorbent and photocatalyst for removal of ibuprofen as pharmaceutical waste. Hexagonal flake-like hematite was obtained following calcination at 500 °C with the average size was measured at 1-3 µm. Increasing the calcination temperature to 700 °C transformed the uniform hexagonal structure into cubic shape morphology. Hematite also showed high thermal stability with increasing the calcination temperatures; however, the surface area was reduced from 47 m2 /g to 9 m2 /g. FTIR analysis further confirmed the formation Fe-O-Fe bonds, and the main constituent elements of Fe and O were observed in EDX analysis for all samples. α-Fe2 O3 samples have an average adsorption capacity of 55-25.5 mg/g at 12-22% of removal efficiency when used as adsorbent for ibuprofen. The adsorption capacity was reduced as the calcination temperatures increased due to the reduction of available surface area of the hexagonal flakes after transforming into cubes. Photocatalytic degradation of ibuprofen using hematite flakes achieved 50% removal efficiency; meanwhile, combination of adsorption and photocatalytic degradation further removed 80% of ibuprofen in water/hexane mixtures.- Published
- 2021
- Full Text
- View/download PDF
23. Barium promoted Ni/Sm 2 O 3 catalysts for enhanced CO 2 methanation.
- Author
-
Ayub NA, Bahruji H, and Mahadi AH
- Abstract
Low temperature CO
2 methanation is a favorable pathway to achieve high selectivity to methane while increasing the stability of the catalysts. A Ba promoted Ni/Sm2 O3 catalyst was investigated for CO2 methanation at atmospheric pressure with the temperature ranging from 200-450 °C. 5Ni-5Ba/Sm2 O3 showed significant enhancement of CO2 conversion particularly at temperatures ≤ 300 °C compared to Ni/Sm2 O3 . Incorporation of Ba into 5Ni/Sm2 O3 improved the basicity of the catalysts and transformed the morphology of Sm2 O3 from random structure into uniform groundnut shape nanoparticles. The uniformity of Sm2 O3 created interparticle porosity that may be responsible for efficient heat transfer during a long catalytic reaction. Ba is also postulated to catalyze oxygen vacancy formation on Sm2 O3 under a reducing environment presumably via isomorphic substitution. The disappearance of a high temperature (∼600 °C) reduction peak in H2 -TPR analysis revealed the reducibility of NiO following impregnation with Ba. However, further increasing the Ba loading to 15% formed BaNiO3 -BaNiO2.36 phases which consequently reduced the activity of the Ni-Ba/Sm2 O3 catalyst at low temperature. Ni was suggested to segregate from BaNiO3 -BaNiO2.36 at high temperature thus exhibiting comparable activity with Ni/Sm2 O3 at 450 °C., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2021
- Full Text
- View/download PDF
24. Identification of C 2 -C 5 products from CO 2 hydrogenation over PdZn/TiO 2 -ZSM-5 hybrid catalysts.
- Author
-
Ruiz Esquius J, Bahruji H, Bowker M, and Hutchings GJ
- Abstract
The combination of a methanol synthesis catalyst and a solid acid catalyst opens the possibility to obtain olefins or paraffins directly from CO2 and H2 in one step. In this work several PdZn/TiO2-ZSM-5 hybrid catalysts were employed under CO2 hydrogenation conditions (240-360 °C, 20 bar, CO2/N2/H2 = 1 : 1 : 3) for the synthesis of CH3OH, consecutive dehydration to dimethyl ether and further oxygenate conversion to hydrocarbons. No significant changes after 36 h reaction on the methanol synthesis catalyst (PdZn/TiO2) were observed by XRD, XAS or XPS. No olefins were observed, indicating that light olefins undergo further hydrogenation under the reaction conditions, yielding the corresponding alkanes. Increasing the aluminium sites in the zeolites (Si : Al ratio 80 : 1, 50 : 1 and 23 : 1) led to a higher concentration of mild Brønsted acid sites, promoting hydrocarbon chain growth.
- Published
- 2021
- Full Text
- View/download PDF
25. Utilization of red mud waste into mesoporous ZSM-5 for methylene blue adsorption-desorption studies.
- Author
-
Tehubijuluw H, Subagyo R, Yulita MF, Nugraha RE, Kusumawati Y, Bahruji H, Jalil AA, Hartati H, and Prasetyoko D
- Subjects
- Adsorption, Kinetics, Microscopy, Electron, Transmission, Spectroscopy, Fourier Transform Infrared, X-Ray Diffraction, Methylene Blue, Water Pollutants, Chemical
- Abstract
Red mud as industrial waste from bauxite was utilized as a precursor for the synthesis of mesoporous ZSM-5. A high concentration of iron oxide in red mud was successfully removed using alkali fusion treatment. Mesoporous ZSM-5 was synthesized using cetyltrimethylammonium bromide (CTABr) as a template via dual-hydrothermal method, and the effect of crystallization time was investigated towards the formation of mesopores. Characterization using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N
2 adsorption-desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) indicated the formation of cubic crystallite ZSM-5 with high surface area and mesopore volume within 6 h of crystallization. Increasing the crystallization time revealed the evolution of highly crystalline ZSM-5; however, the surface area and mesoporosity were significantly reduced. The effect of mesoporosity was investigated on the adsorption of methylene blue (MB). Kinetic and thermodynamic analysis of MB adsorption on mesoporous ZSM-5 was carried out at a variation of adsorption parameters such as the concentration of MB solution, the temperatures of solution, and the amount of adsorbent. Finally, methanol, 1-butanol, acetone, hydrochloric acid (HCl), and acetonitrile were used as desorbing agents to investigate the reusability and stability of mesoporous ZSM-5 as an adsorbent for MB removal., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2021
- Full Text
- View/download PDF
26. Lewis acid Ni/Al-MCM-41 catalysts for H 2 -free deoxygenation of Reutealis trisperma oil to biofuels.
- Author
-
Nugraha RE, Prasetyoko D, Bahruji H, Suprapto S, Asikin-Mijan N, Oetami TP, Jalil AA, Vo DN, and Taufiq-Yap YH
- Abstract
The activity of mesoporous Al-MCM-41 for deoxygenation of Reutealis trisperma oil (RTO) was enhanced via modification with NiO nanoparticles. Deoxygenation at atmospheric pressure and under H
2 free conditions required acid catalysts to ensure the removal of the oxygenated fragments in triglycerides to form liquid hydrocarbons. NiO at different weight loadings was impregnated onto Al-MCM-41 and the changes of Lewis/Brønsted acidity and mesoporosity of the catalysts were investigated. The activity of Al-MCM-41 was enhanced when impregnated with NiO due to the increase of Lewis acidity originating from NiO nanoparticles and the mesoporosity of Al-MCM-41. Increasing the NiO loading enhanced the Lewis acidity but not Brønsted acidity, leading to a higher conversion towards liquid hydrocarbon yield. Impregnation with 10% of NiO on Al-MCM-41 increased the conversion of RTO to hydrocarbons via the deoxygenation pathway and reduced the products from cracking reaction, consequently enhancing the green diesel (C11-C18) hydrocarbon products., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2021
- Full Text
- View/download PDF
27. Enhanced CO 2 methanation at mild temperature on Ni/zeolite from kaolin: effect of metal-support interface.
- Author
-
Sholeha NA, Mohamad S, Bahruji H, Prasetyoko D, Widiastuti N, Abdul Fatah NA, Jalil AA, and Taufiq-Yap YH
- Abstract
Catalytic CO
2 hydrogenation to CH4 offers a viable route for CO2 conversion into carbon feedstock. The research aimed to enhance CO2 conversion at low temperature and to increase the stability of Ni catalysts using zeolite as a support. NaZSM-5 (MFI), NaA (LTA), NaY (FAU), and NaBEA (BEA) synthesized from kaolin were impregnated with 15% Ni nanoparticles in order to elucidate the effect of surface area, porosity and basicity of the zeolite in increasing Ni activity at mild temperature of ∼200 °C. A highly dispersed Ni catalyst was produced on high surface area NaY meanwhile the mesoporosity of ZSM-5 has no significant effect in improving Ni dispersion. However, the important role of zeolite mesoporosity was observed on the stability of the catalyst. Premature deactivation of Ni/NaA within 10 h was due to the relatively small micropore size that restricted the CO2 diffusion, meanwhile Ni/NaZSM-5 with a large mesopore size exhibited catalytic stability for 40 h of reaction. Zeolite NaY enhanced Ni activity at 200 °C to give 21% conversion with 100% CH4 selectivity. In situ FTIR analysis showed the formation of hydrogen carbonate species and formate intermediates at low temperatures on Ni/NaY, which implied the efficiency of electron transfer from the basic sites of NaY during CO2 reduction. The combination of Ni/NaY interfacial interaction and NaY surface basicity promoted CO2 methanation reaction at low temperature., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2021
- Full Text
- View/download PDF
28. Size tunable mesoporous carbon microspheres using Pluronic F127 and gelatin as co-template for removal of ibuprofen.
- Author
-
Ulfa M, Prasetyoko D, Mahadi AH, and Bahruji H
- Subjects
- Carbon, Gelatin, Ibuprofen, Kinetics, Poloxamer, Microspheres
- Abstract
Size tunable mesoporous carbon microspheres, MCMs were obtained using Pluronic F127 and gelatin in co-templating method via hydrothermal and pyrolysis treatments. The presence of gelatin increased the mechanical strength of Pluronic F127 which can sustain the uniform microspherical structure of carbon following pyrolysis at 950 °C. The diameter of MCMs were controlled by variation of weight ratios between Pluronic F127 to gelatin from 1:0.01 to 1:1. MCMs exhibited inter-particulate mesoporous structure with high thermal stability (<500 °C). The MCMs were used as adsorbent for removal of ibuprofen and the kinetic studies using linear regression analysis revealed the adsorption fits pseudo second-order kinetic. The rate of adsorption and the amount of adsorbed ibuprofen were correlated well with the surface area and the crystallite size of MCMs. The efficiencies of ibuprofen adsorption on MCMs were also investigated when ibuprofen was dissolved at different concentration of water and hexane mixtures, the effect temperature variation and the amount MCMs to the volume of ibuprofen solution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
29. Pd local structure and size correlations to the activity of Pd/TiO 2 for photocatalytic reforming of methanol.
- Author
-
Abdullah N, Bahruji H, Rogers SM, Wells PP, Catlow CRA, and Bowker M
- Abstract
The interaction between Pd and TiO2 for promoting photocatalytic activity was investigated by tailoring the size of Pd nanoparticles and monitoring the photocatalytic activity of methanol photo-reforming reaction for hydrogen gas production. We show that at 0.6 wt% Pd loading, the catalyst with highly dispersed nanoparticles obtained at 1 °C temperature exhibits superior photocatalytic activity for hydrogen gas production. At different weights of Pd loading, tailoring two sets of catalysts with different structural properties provides correlation between the changes in the Pd local structures and the rate of hydrogen production. The impact of controlling the structural properties of metal nanoparticles on influencing H2 production outweighs the effect of metal loading variation. The differences of Pd/TiO2 activity at the different metal loadings were correlated with the changes in the Pd local structure consequently affecting the electronic transfer and photocatalytic efficiency.
- Published
- 2019
- Full Text
- View/download PDF
30. Rock-crushing derived hydrogen directly supports a methanogenic community: significance for the deep biosphere.
- Author
-
Parkes RJ, Berlendis S, Roussel EG, Bahruji H, Webster G, Oldroyd A, Weightman AJ, Bowker M, Davies PR, and Sass H
- Subjects
- Bacteria classification, Bacteria genetics, Bacteria metabolism, Biodiversity, Chemical Phenomena, DNA Restriction Enzymes genetics, DNA, Archaeal genetics, DNA, Bacterial genetics, Euryarchaeota classification, Euryarchaeota genetics, Euryarchaeota metabolism, Hydrogen analysis, Mechanical Phenomena, Methane analysis, Phylogeny, RNA, Ribosomal, 16S genetics, Hydrogen metabolism, Methane biosynthesis, Microbiota, Silicon Dioxide chemistry
- Abstract
Microbial populations exist to great depths on Earth, but with apparently insufficient energy supply. Earthquake rock fracturing produces H
2 from mechanochemical water splitting, however, microbial utilization of this widespread potential energy source has not been directly demonstrated. Here, we show experimentally that mechanochemically generated H2 from granite can be directly, long-term, utilized by a CH4 producing microbial community. This is consistent with CH4 formation in subsurface rock fracturing in the environment. Our results not only support water splitting H2 generation as a potential deep biosphere energy source, but as an oxidant must also be produced, they suggest that there is also a respiratory oxidant supply in the subsurface which is independent of photosynthesis. This may explain the widespread distribution of facultative aerobes in subsurface environments. A range of common rocks were shown to produce mechanochemical H2 , and hence, this process should be widespread in the subsurface, with the potential for considerable mineral fuelled CH4 production., (© 2018 The Authors. Environmental Microbiology Reports published by Society for Applied Microbiology and John Wiley & Sons Ltd.)- Published
- 2019
- Full Text
- View/download PDF
31. Solvent Free Synthesis of PdZn/TiO 2 Catalysts for the Hydrogenation of CO 2 to Methanol.
- Author
-
Bahruji H, Esquius JR, Bowker M, Hutchings G, Armstrong RD, and Jones W
- Abstract
Catalytic upgrading of CO
2 to value-added chemicals is an important challenge within the chemical sciences. Of particular interest are catalysts which are both active and selective for the hydrogenation of CO2 to methanol. PdZn alloy nanoparticles supported on TiO2 via a solvent-free chemical vapour impregnation method are shown to be effective for this reaction. This synthesis technique is shown to minimise surface contaminants, which are detrimental to catalyst activity. The effect of reductive heat treatments on both structural properties of PdZn/TiO2 catalysts and rates of catalytic CO2 hydrogenation are investigated. PdZn nanoparticles formed upon reduction showed high stability towards particle sintering at high reduction temperature with average diameter of 3-6 nm to give 1710 mmol kg-1 h of methanol. Reductive treatment at high temperature results in the formation of ZnTiO3 as well as PdZn, and gives the highest methanol yield.- Published
- 2018
- Full Text
- View/download PDF
32. PdZn catalysts for CO 2 hydrogenation to methanol using chemical vapour impregnation (CVI).
- Author
-
Bahruji H, Bowker M, Jones W, Hayward J, Ruiz Esquius J, Morgan DJ, and Hutchings GJ
- Abstract
The formation of PdZn bimetallic alloys on ZnO, TiO
2 and Al2 O3 supports was investigated, together with the effect of alloy formation on the CO2 hydrogenation reaction. The chemical vapour impregnation (CVI) method produced PdZn nanoparticles with diameters of 3-6 nm. X-ray photoelectron spectroscopy and X-ray diffraction revealed the changes in the structure of the PdZn alloy that help stabilise formate intermediates during methanol synthesis. PdZn supported on TiO2 exhibits high methanol productivity of 1730 mmol kgcat h-1 h-1 that is associated with the high dispersion of the supported PdZn alloy.- Published
- 2017
- Full Text
- View/download PDF
33. Photodegradation of organic pollutants in water and green hydrogen production via methanol photoreforming of doped titanium oxide nanoparticles.
- Author
-
Rico-Oller B, Boudjemaa A, Bahruji H, Kebir M, Prashar S, Bachari K, Fajardo M, and Gómez-Ruiz S
- Subjects
- Green Chemistry Technology, Methylene Blue chemistry, Photolysis, Ultraviolet Rays, Hydrogen chemistry, Metal Nanoparticles chemistry, Methanol chemistry, Titanium chemistry, Waste Disposal, Fluid methods, Water Pollutants, Chemical chemistry
- Abstract
Novel nanomaterials based on doped TiO2 nanoparticles with different morphological, textural and band-gap properties have been synthesized using scalable methods. The influence of synthetic parameters such as titanium source (titanium(IV) isopropoxide and titanium(IV) butoxide), doping quantity (0%, 2% or 5% Zn), acidic solution for the hydrolysis reaction (ascorbic acid, nitric acid) and calcination temperatures (500°C and 600°C) was simultaneously investigated. The obtained nanomaterials were characterized by different methods and photocatalytic tests of methylene blue (MB) degradation under UV-light were conducted to determine their activity. The results revealed that the synthesized nanomaterials are porous aggregates with very high crystallinity and are mainly composed of the anatase phase; although their physical properties vary depending on the different synthetic parameters employed. These changes are able to modify the apparent rate constant of the degradation of MB up to one order of magnitude, indicating, substantial changes in their photoactivity. Hybrid materials TiO2-Pd nanoparticles have also been prepared, characterized and tested for hydrogen production using photocatalytic methanol reforming where supported palladium nanoparticles acted as co-catalyst. Furthermore, the hybrid materials TiO2-Pd nanoparticles were studied in photocatalytic tests of methylene blue degradation under visible LED-light. The results obtained in the production of hydrogen from the photocatalytic reforming of methanol by hybrid materials suggest that the reported hybrid systems could be suitable photocatalysts for future sustainable hydrogen production upon tuning of the morphological, textural and band gap energy properties to allow processes to be carried out under visible light., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.