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Bano S, Tariq SR, Anjum T, Najam M, Usman M, Yasin M, Shafi HZ, Khan AL. Development of highly permselective Mixed Matrix Membranes comprising of polyimide and Ln-MOF for CO 2 capture. CHEMOSPHERE 2022; 307:136051. [PMID: 35977565 DOI: 10.1016/j.chemosphere.2022.136051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/07/2022] [Accepted: 08/08/2022] [Indexed: 05/26/2023]
Abstract
Mixed Matrix Membranes (MMMs) with hybrid organic-inorganic characteristics offer a strong alternative to traditional polymer-based membranes to reduce the trade-off between gas permeability and selectivity. This work incorporated lanthanum-Metal Organic Frameworks in the Matrimid to fabricate MMMs. To understand the effects of nano-filler on membranes' morphology, porosity, thermal stability, and chemical composition, MMMs were fabricated with three different loadings of nano-filler, i.e., 10, 20 and 30 wt%. The selectivity and permeability of CH4, CO2, and N2 gases through MMMs were investigated at 10 bar pressure and temperatures ranging from 25 to 55 °C. All MMMs exhibited enhanced CO2 permeation with increased nano-filler loading because the porous nano-filler provided additional channels and fractional free volume in the polymer matrix. The 30 wt% loaded membrane showed a 183% increase in permeability of CO2 than neat membrane. With increasing nano-filler loading, the selectivity of MMMs increased from 34.1 to 48.45 for CO2/N2 and from 36.2 to 54.67 for CO2/CH4, confirming the absence of membrane defects, improved filler/polymer interface, and excellent dispersion of nano-filler in the polymer matrix. The results proved that these membranes could be further used for gas separation industrial applications.
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Affiliation(s)
- Sadia Bano
- Department of Chemistry, Lahore College for Women University, Lahore, Pakistan
| | - Saadia Rashid Tariq
- Department of Chemistry, Lahore College for Women University, Lahore, Pakistan.
| | - Tanzila Anjum
- Department of Chemical Engineering, COMSATS, University Islamabad, Lahore Campus, Pakistan
| | - Mohsin Najam
- Department State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Muhammad Usman
- Center of Research Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals (KFUPM), Dharan, 31261, Saudi Arabia.
| | - Muhammad Yasin
- Department of Chemical Engineering, COMSATS, University Islamabad, Lahore Campus, Pakistan
| | - H Z Shafi
- National Institute of Lasers and Optronics College (NILOP-C), Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad, 45650, Pakistan
| | - Asim Laeeq Khan
- Department of Chemical Engineering, COMSATS, University Islamabad, Lahore Campus, Pakistan.
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Potemkin DI, Maslov DK, Loponov K, Snytnikov PV, Shubin YV, Plyusnin PE, Svintsitskiy DA, Sobyanin VA, Lapkin AA. Porous Nanocrystalline Silicon Supported Bimetallic Pd-Au Catalysts: Preparation, Characterization, and Direct Hydrogen Peroxide Synthesis. Front Chem 2018; 6:85. [PMID: 29637068 PMCID: PMC5880941 DOI: 10.3389/fchem.2018.00085] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/12/2018] [Indexed: 11/13/2022] Open
Abstract
Bimetallic Pd-Au catalysts were prepared on the porous nanocrystalline silicon (PSi) for the first time. The catalysts were tested in the reaction of direct hydrogen peroxide synthesis and characterized by standard structural and chemical techniques. It was shown that the Pd-Au/PSi catalyst prepared from conventional H2[PdCl4] and H[AuCl4] precursors contains monometallic Pd and a range of different Pd-Au alloy nanoparticles over the oxidized PSi surface. The PdAu2/PSi catalyst prepared from the [Pd(NH3)4][AuCl4]2 double complex salt (DCS) single-source precursor predominantly contains bimetallic Pd-Au alloy nanoparticles. For both catalysts the surface of bimetallic nanoparticles is Pd-enriched and contains palladium in Pd0 and Pd2+ states. Among the catalysts studied, the PdAu2/PSi catalyst was the most active and selective in the direct H2O2 synthesis with H2O2 productivity of 0.5 mol gPd-1 h-1 at selectivity of 50% and H2O2 concentration of 0.023 M in 0.03 M H2SO4-methanol solution after 5 h on stream at −10°C and atmospheric pressure. This performance is due to high activity in the H2O2 synthesis reaction and low activities in the undesirable H2O2 decomposition and hydrogenation reactions. Good performance of the PdAu2/PSi catalyst was associated with the major part of Pd in the catalyst being in the form of the bimetallic Pd-Au nanoparticles. Porous silicon was concluded to be a promising catalytic support for direct hydrogen peroxide synthesis due to its inertness with respect to undesirable side reactions, high thermal stability, and conductivity, possibility of safe operation at high temperatures and pressures and a well-established manufacturing process.
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Affiliation(s)
- Dmitriy I Potemkin
- Laboratory of the Energy-Efficient Catalytic Processes, Novosibirsk State University, Novosibirsk, Russia.,Department of Heterogeneous Catalysis, Boreskov Institute of Catalysis, Novosibirsk, Russia
| | - Dmitry K Maslov
- Department of Heterogeneous Catalysis, Boreskov Institute of Catalysis, Novosibirsk, Russia
| | - Konstantin Loponov
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Pavel V Snytnikov
- Laboratory of the Energy-Efficient Catalytic Processes, Novosibirsk State University, Novosibirsk, Russia.,Department of Heterogeneous Catalysis, Boreskov Institute of Catalysis, Novosibirsk, Russia
| | - Yuri V Shubin
- Laboratory of the Energy-Efficient Catalytic Processes, Novosibirsk State University, Novosibirsk, Russia.,Laboratory of the Rare Platinum Metals Chemistry, Nikolaev Institute of Inorganic Chemistry, Novosibirsk, Russia
| | - Pavel E Plyusnin
- Laboratory of the Energy-Efficient Catalytic Processes, Novosibirsk State University, Novosibirsk, Russia.,Laboratory of the Rare Platinum Metals Chemistry, Nikolaev Institute of Inorganic Chemistry, Novosibirsk, Russia
| | - Dmitry A Svintsitskiy
- Laboratory of the Energy-Efficient Catalytic Processes, Novosibirsk State University, Novosibirsk, Russia.,Department of Heterogeneous Catalysis, Boreskov Institute of Catalysis, Novosibirsk, Russia
| | - Vladimir A Sobyanin
- Department of Heterogeneous Catalysis, Boreskov Institute of Catalysis, Novosibirsk, Russia
| | - Alexei A Lapkin
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom.,Cambridge Centre for Advanced Research and Education in Singapore Ltd., Singapore, Singapore
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Dynamic molecular interactions between polyurethane and ZIF-8 in a polymer-MOF nanocomposite: Microstructural, thermo-mechanical and viscoelastic effects. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.05.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Recent Development of Catalysts for Removal of Volatile Organic Compounds in Flue Gas by Combustion: A Review. J CHEM-NY 2016. [DOI: 10.1155/2016/8324826] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Volatile organic compounds (VOCs) emitted from anthropogenic sources pose direct and indirect hazards to both atmospheric environment and human health due to their contribution to the formation of photochemical smog and potential toxicity including carcinogenicity. Therefore, to abate VOCs emission, the catalytic oxidation process has been extensively studied in laboratories and widely applied in various industries. This report is mainly focused on the benzene, toluene, ethylbenzene, and xylene (BTEX) with additional discussion about chlorinated VOCs. This review covers the recent developments in catalytic combustion of VOCs over noble metal catalysts, nonnoble metal catalysts, perovskite catalysts, spinel catalysts, and dual functional adsorbent-catalysts. In addition, the effects of supports, coke formation, and water effects have also been discussed. To develop efficient and cost-effective catalysts for VOCs removal, further research in catalytic oxidation might need to be carried out to strengthen the understanding of catalytic mechanisms involved.
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Mixed-matrix membranes of zeolitic imidazolate framework (ZIF-8)/Matrimid nanocomposite: Thermo-mechanical stability and viscoelasticity underpinning membrane separation performance. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2015.09.066] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Brahmkhatri VP, Chandra K, Dubey A, Atreya HS. An ultrastable conjugate of silver nanoparticles and protein formed through weak interactions. NANOSCALE 2015; 7:12921-12931. [PMID: 26166696 DOI: 10.1039/c5nr03047a] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In recent years, silver nanoparticles (AgNPs) have attracted significant attention owing to their unique physicochemical, optical, conductive and antimicrobial properties. One of the properties of AgNPs which is crucial for all applications is their stability. In the present study we unravel a mechanism through which silver nanoparticles are rendered ultrastable in an aqueous solution in complex with the protein ubiquitin (Ubq). This involves a dynamic and reversible association and dissociation of ubiquitin from the surface of AgNP. The exchange occurs at a rate much greater than 25 s(-1) implying a residence time of <40 ms for the protein. The AgNP-Ubq complex remains stable for months due to steric stabilization over a wide pH range compared to unconjugated AgNPs. NMR studies reveal that the protein molecules bind reversibly to AgNP with an approximate dissociation constant of 55 μM and undergo fast exchange. At pH > 4 the positively charged surface of the protein comes in contact with the citrate capped AgNP surface. Further, NMR relaxation-based experiments suggest that in addition to the dynamic exchange, a conformational rearrangement of the protein takes place upon binding to AgNP. The ultrastability of the AgNP-Ubq complex was found to be useful for its anti-microbial activity, which allowed the recycling of this complex multiple times without the loss of stability. Altogether, the study provides new insights into the mechanism of protein-silver nanoparticle interactions and opens up new avenues for its application in a wide range of systems.
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