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Vega G, Quintanilla A, López P, Belmonte M, Casas JA. Structured Reactors Based on 3D Fe/SiC Catalysts: Understanding the Effects of Mixing. Ind Eng Chem Res 2022; 61:11678-11690. [PMID: 36636039 PMCID: PMC9828541 DOI: 10.1021/acs.iecr.2c01611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 01/16/2023]
Abstract
The application of structured reactors provides a number of advantages in chemical processes. In this paper, two different three-dimensional (3D) Fe/SiC catalysts with a square cell geometry have been manufactured by Robocasting: monoliths (D = 14 and H = 15 mm) and meshes (D = 24 and H = 2 mm) and studied in the catalytic phenol oxidation by hydrogen peroxide (H2O2) for the sustainable production of dihydroxybenzenes (DHBZ). The fluid dynamics, catalytic performance, reaction rates, external mass transport limitation, and catalyst stability have been compared in three different reactors, monolithic fixed-bed reactor, multimesh fixed-bed reactor, and monolithic stirrer reactor, at selected operating conditions. The results show that the mechanical stirring of the 3D Fe/SiC monoliths avoids the external mass transfer limitation caused by the presence of oxygen bubbles in the channels (produced from the HO x · species in autoscavenging radical reactions). In addition, the backmixing has a positive effect on the efficient consumption of H2O2 but an adverse effect on the phenol selectivity to DHBZ since they are overoxidized to tar products at longer contact times. On the other hand, the wall porosity, and not the backmixing, affects the susceptibility of the 3D Fe/SiC catalyst to the Fe leaching, as occurs in the mesh structures. In conclusion, the monoliths operating under plug-flow and external mass transfer limitation in the monolithic fixed-bed reactor (MFB) provide an outstanding phenol selectivity to DHBZ and catalyst stability.
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Affiliation(s)
- Gonzalo Vega
- Department
of Chemical Engineering, Universidad Autónoma
de Madrid, Campus de Cantoblanco, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain,
| | - Asuncion Quintanilla
- Department
of Chemical Engineering, Universidad Autónoma
de Madrid, Campus de Cantoblanco, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain,
| | - Pablo López
- Department
of Chemical Engineering, Universidad Autónoma
de Madrid, Campus de Cantoblanco, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain
| | - Manuel Belmonte
- Institute
of Ceramics and Glass (ICV-CSIC), Campus de Cantoblanco, C/Kelsen 5, 28049 Madrid, Spain
| | - Jose A. Casas
- Department
of Chemical Engineering, Universidad Autónoma
de Madrid, Campus de Cantoblanco, C/Francisco Tomás y Valiente 7, 28049 Madrid, Spain
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Salazar-Aguilar AD, Quintanilla A, López P, Martínez C, Vega-Díaz SM, Casas JA, Miranzo P, Osendi MI, Belmonte M. 3D-Printed Fe/γ-Al 2O 3 Monoliths from MOF-Based Boehmite Inks for the Catalytic Hydroxylation of Phenol. ACS APPLIED MATERIALS & INTERFACES 2022; 14:920-932. [PMID: 34939422 DOI: 10.1021/acsami.1c19755] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The synthesis of dihydroxybenzenes (DHBZ), essential chemical reagents in numerous industrial processes, with a high degree of selectivity and yield from the hydroxylation of phenol is progressively attracting great interest in the catalysis field. Furthermore, the additive manufacturing of catalysts to produce 3D printed monoliths would provide additional benefits to enhance the DHBZ synthesis performance. Herein, 3D cellular Fe/γ-Al2O3 monoliths with a total porosity of 88% and low density (0.43 g·cm-3) are printed by Robocasting from pseudoplastic Fe-metal-organic frameworks (Fe-MOF)-based aqueous boehmite inks to develop catalytic monoliths containing a Fe network of dispersed clusters (≤5 μm), nanoclusters (<50 nm), and nanoparticles (∼20 nm) into the porous ceramic skeleton. The hydroxylation of phenol in the presence of hydrogen peroxide is carried out at different reaction temperatures (65-85 °C) in a flow reactor filled with eight stacked 3D Fe/γ-Al2O3 monoliths and with the following operating conditions: Cphenol,0 = 0.33 M, Cphenol,0/CH2O2,0 = 1:1 molar, WR = 2.2 g, and space time (τ = W·QL-1) = 0-147 gcat·h·L-1. The scaffolds present a good mechanical resistance (∼1 MPa) to be employed in a catalytic reactor and do not show any cracks or damage after the chemical reaction. DHBZ selectivity (SDHBZ) of 100% with a yield (YDHBZ) of 32% due to the presence of the Fe network in the monoliths is reported at 85 °C, which represents an improved synthesis performance as compared to that obtained by using the conventional Enichem process and the well-known titanium silicalite-1 catalysts (SDHBZ = 99.1% and YDHBZ = 29.6% at 80 °C). This printing strategy allows manufacturing novel 3D structured catalysts for the synthesis of critical chemical compounds with higher reaction efficiencies.
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Affiliation(s)
- Alma D Salazar-Aguilar
- Departamento de Ingeniería Química, Tecnológico Nacional de México, Instituto Tecnológico de Celaya, Av. García Cubas Pte # 600 esq. Avenida Tecnológico, 38010 Celaya, Guanajuato, Mexico
- Chemical Engineering Department, Universidad Autónoma de Madrid, Ctra. Colmenar km 15, 28049 Madrid, Spain
- Institute of Ceramics and Glass (ICV-CSIC), Campus de Cantoblanco, Kelsen 5, 28049 Madrid, Spain
| | - Asuncion Quintanilla
- Chemical Engineering Department, Universidad Autónoma de Madrid, Ctra. Colmenar km 15, 28049 Madrid, Spain
| | - Pablo López
- Chemical Engineering Department, Universidad Autónoma de Madrid, Ctra. Colmenar km 15, 28049 Madrid, Spain
| | - Carla Martínez
- Chemical Engineering Department, Universidad Autónoma de Madrid, Ctra. Colmenar km 15, 28049 Madrid, Spain
| | - Sofía M Vega-Díaz
- Departamento de Ingeniería Química, Tecnológico Nacional de México, Instituto Tecnológico de Celaya, Av. García Cubas Pte # 600 esq. Avenida Tecnológico, 38010 Celaya, Guanajuato, Mexico
| | - José A Casas
- Chemical Engineering Department, Universidad Autónoma de Madrid, Ctra. Colmenar km 15, 28049 Madrid, Spain
| | - Pilar Miranzo
- Institute of Ceramics and Glass (ICV-CSIC), Campus de Cantoblanco, Kelsen 5, 28049 Madrid, Spain
| | - M Isabel Osendi
- Institute of Ceramics and Glass (ICV-CSIC), Campus de Cantoblanco, Kelsen 5, 28049 Madrid, Spain
| | - Manuel Belmonte
- Institute of Ceramics and Glass (ICV-CSIC), Campus de Cantoblanco, Kelsen 5, 28049 Madrid, Spain
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Engineering titanium-organic framework decorated silver molybdate and silver vanadate as antimicrobial, anticancer agents, and photo-induced hydroxylation reactions. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113572] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Direct Hydroxylation of Phenol to Dihydroxybenzenes by H2O2 and Fe-based Metal-Organic Framework Catalyst at Room Temperature. Catalysts 2020. [DOI: 10.3390/catal10020172] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A semi-crystalline iron-based metal-organic framework (MOF), in particular Fe-BTC, that contained 20 wt.% Fe, was sustainably synthesized at room temperature and extensively characterized. Fe-BTC nanopowders could be used as an efficient heterogeneous catalyst for the synthesis of dihydroxybenzenes (DHBZ), from phenol with hydrogen peroxide (H2O2), as oxidant under organic solvent-free conditions. The influence of the reaction temperature, H2O2 concentration and catalyst dose were studied in the hydroxylation performance of phenol and MOF stability. Fe-BTC was active and stable (with negligible Fe leaching) at room conditions. By using intermittent dosing of H2O2, the catalytic performance resulted in a high DHBZ selectivity (65%) and yield (35%), higher than those obtained for other Fe-based MOFs that typically require reaction temperatures above 70 °C. The long-term experiments in a fixed-bed flow reactor demonstrated good Fe-BTC durability at the above conditions.
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