Swiss CAT+, a Data-driven Infrastructure for Accelerated Catalysts Discovery and Optimization

The Catalysis Hub – Swiss CAT+ is a new infrastructure project funded by ETH-domain, co-headed by EPFL and ETHZ. It offers the scientific community a unique integrated technology platform combining automated and high-throughput experimentation with advanced computational data analysis to accelerate the discoveries in the field of sustainable catalytic technologies. Divided into two hubs of expertise, homogeneous catalysis at EPFL and heterogeneous catalysis at ETHZ, the platform is open to academic and private research groups. Following a multi-year investment plan, both hubs have acquired and developed several high-end robotic platforms devoted to the synthesis, characterization, and testing of large numbers of molecular and solid catalysts. The hardware is associated with a fully digitalized experimental workflow and a specific data management strategy to support closed-loop experimentation and advanced computational data analysis

Elimination des traces d hydrocarbures aromatiques polycycliques en milieu aqueux par l hémoglobine bovine immobilisée dans des matériaux siliciques mésoporeux

Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants très peu réactifs et cancérigènes retrouvés dans les eaux de rejet des raffineries. Les traitements actuellement appliqués en raffineries permettent de rejeter dans l'environnement des eaux ne contenant que des traces de HAP. Néanmoins, une nouvelle directive cadre européenne sur l'eau veut que d'ici 2015 la concentration en HAP dans les eaux de rejet des raffineries soit divisée par 100. Pour parvenir à cet objectif, les biotechnologies enzymatiques, de part leur efficacité et leur faible impact sur l'environnement, sont très prometteuses. Au cours de cette thèse, l'activité de type peroxydase de l'hémoglobine bovine (Hb) vis-à-vis de l'oxydation des HAP a été étudiée. Après une optimisation du procédé et une étude complète des mécanismes catalytiques, la protéine a été immobilisée sur différentes silices mésoporeuses afin d'obtenir un biomatériau efficace pouvant être utilisé en industrie. Pour terminer, Hb a été co-encapsulée avec la glucose oxydase (GOx) dans une silice mésoporeuse originale structurée par des tensioactifs naturels afin de produire in situ le peroxyde d'hydrogène à partir du glucose et de O2 dissout dans le milieu. Les résultats ont permis d'affiner les connaissances sur les mécanismes catalytiques de Hb, d'optimiser le procédé en milieu homogène et hétérogène afin d'aboutir à une élimination de plus de 80 % des polluants dans des conditions similaires aux eaux de rejet, de produire un biomatériau très efficace d'un point de vue catalytique et améliorant la stabilité de la protéine vis-à-vis de différents paramètres, ainsi qu'un nano-bioréacteur bi-encapsulé très prometteur.Polycyclic aromatic hydrocarbons (PAH) are very stable and carcinogenic pollutants found in petroleum refineries waste waters. Today's processes applied in refineries produce waste waters showing PAH trace concentrations. Nevertheless, a recent European legislation aims to divide the PAH concentration in petroleum refineries waste waters by 100. To reach this objective, enzymatic biotechnologies, because of their high efficiency and low environmental threatens, are very interesting. During this thesis, the peroxidase-like activity of bovine hemoglobin (Hb) toward PAH oxidation has been studied. After an optimization of the process and a complete study of the catalytic mechanisms, the protein has been immobilized on a mesoporous silica support to obtain an industrial efficient biomaterial. Finally, Hb and glucose oxidase (GOx) have been entrapped together into original mesoporous silica, structured with a natural surfactant, to produce hydrogen peroxide in situ from glucose and O2 dissolved in the medium. Results allowed gaining knowledge about Hb catalytic mechanisms, optimizing the process reaching more than 80% elimination of the overall pollutants, producing a very efficient catalytic biomaterial showing better stability of Hb toward various parameters, and also a very promising Hb/GOx nano-bioreactor.MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Durable PROX catalyst based on gold nanoparticles and hydrophobic silica

SSCI-VIDE+ING+KGI:ATU:VCAInternational audience3 nm gold nanoparticles obtained by direct chemical reduction of AuPPh3Cl in the presence of hydrophobic silica are highly active andselective over a prolonged period of time in the low temperatureoxidation of CO in the presence of hydrogen

Oxidation reactions using air as oxidant thanks to silica nanoreactors containing GOx/peroxidases bienzymatic systems

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Catalase-like activity of bovine met-hemoglobin: interaction with the pseudo-catalytic peroxidation of anthracene traces in aqueous medium

International audienceHemoglobin is a member of hemoprotein superfamily whose main role is to transport O2 in vertebrate organisms. It has also two known promiscuous enzymatic activities, namely peroxidase and oxygenase. Here we show for the first time that bovine hemoglobin also presents a catalase-like activity characterized by a Vmax of 344 µM/min, a KM of 24 mM and a kcat equal to 115 min-1. For high anthracene and hemoglobin concentrations and low hydrogen peroxide concentrations, this activity inhibits the expected oxidation of anthracene, which occurs through a peroxidase-like mechanism. Anthracene belongs to the polycyclic aromatic hydrocarbons family whose members are carcinogenic and persistent pollutants found in industrial waste waters. Our results show that anthracene oxidation by hemoglobine and hydrogen peroxide follows a typical bi-bi ping-pong mechanism with a Vmax equal to 0.250 µM/min, KM(H2O2) of 80 µM, KM(ANT) of 1.1 µM and kcat of 0.17 min-1. The oxidation of anthracene is shown to be pseudo-catalytic because an excess of hemoglobin and hydrogen peroxide is required to make PAH completely disappear. Thus bovine hemoglobin presents, in different degrees, all the catalytic activities of the hemoprotein group which makes it a very interesting protein for biotechnological processes and with which one can study structure-activity relationships

EPR studies of new mesostructured silica synthesis and hemoglobin encapsulation

International audienceEnzyme encapsulation in ordered porous silica has been modified by introducing a natural surfactant such as lecithin during the sol-gel process. beta-lactose has been used as the enzyme protecting agent and tetraethoxysilane as the source of Silica in all hydroalcoholic media. In the present study, the EPR spectroscopy of paramagnetic probes has allowed to monitor the formation of mesophases and the condensation of silica in all isotropic three-dimensional structure, named Sponge Mesoporous Silica, with a pore size of 6 nm and a specific Surface area of 600 m(2)/g. Different techniques of characterization (nitrogen sorption, XRD, TEM, SEM) have been used to study the influence of the different reactants oil the. structure of the materials. Hemoglobin has been encapsulated in the different materials and its catalytic pseudo peroxydase activity has been evaluated

Accelerated Exploration of Heterogeneous CO2 Hydrogenation Catalysts by Bayesian Optimized High-throughput and Automated Experimentation.

Automated high-throughput platforms and Artificial Intelligence (AI) are already accelerating discovery and optimization in various fields of chemistry and chemical engineering. However, despite some promising solutions, little to no attempts have targeted the full heterogeneous catalyst discovery workflow, with most chemistry laboratories continuing to perform research with a traditional one-at-a-time experiment approach and limited digitization. In this work, we present a closed-loop data-driven approach targeting the optimization of catalysts’ composition for the direct transformation of carbon dioxide (CO2) into methanol, by combining Bayesian Optimization (BO) algorithm, automated synthesis by incipient wetness impregnation and high-throughput catalytic performance evaluation in fixed bed mode. The BO algorithm optimized a four-objective function simultaneously (high CO2 conversion, high methanol selectivity, low methane selectivity, and low metal cost) with a total of 11 parameters (4 supports, 6 metals salts, and one promoter). In 6 weeks, 144 catalysts were synthesized and tested, with limited manual laboratory activity. The results show a significant improvement in the objectives at the end of each iteration. Between the first and fifth catalyst generation, the average CO2 conversion and methanol formation rates have been multiplied by 5.7 and 12.6 respectively, while simultaneously reducing the methane production rate by 3.2 and dividing the metal cost by 6.3 times. Notably, through the exploration process, the BO algorithm rapidly focuses on copper-based catalysts supported on zirconia doped with Zinc and/or Cerium, with the best catalysts, according to the model, showing an optimized composition of 1.85wt% Cu, 0.69wt% Zn, and 0.05wt% Ce supported on ZrO2. When changing the objective, i.e. removing the metal cost as a constrain, the BO algorithm suggests compositions centered on Indium-based catalysts, highlighting an alternative family of catalysts, testifying of the algorithm adaptability and the reusability of the data when targeting different objectives. In only 30 days, the BO, coupled with automated synthesis and high-throughput testing, has been able to replicate the major development stages in the field of heterogeneous catalysts research for CO2 conversion to methanol, made over of the last 100 years with a conventional experimental approach. This data-driven approach proves to be very efficient in exploring and optimizing catalyst composition from the vast multi-parameter space towards multiple performance objectives simultaneously and could be easily extrapolated to different parameter spaces, objectives, and be transposed to other applications

Phospholipid-templated silica nanocapsules as efficient polyenzymatic biocatalysts

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Maximizing utilization of reactivated and left-over catalysts in heavy gas oil hydrotreater: A case study of ADNOC Refining

Recently, ADNOC Refining Research Center (ARRC) has studied the possibility to maximize the reutilization of left-overs and reactivated hydrodesulfurization catalysts for one of its hydrotreater producing Ultra Low Sulfur Diesel (ULSD) from Heavy Gas Oil (HGO). Based on the refinery inventory, several catalyst configurations composed of different amounts of reactivated and fresh CoMo catalyst, including a full reactivated configuration having a stacked CoMo/NiMo/CoMo combination (50/25/25), have been tested in a pilot-plant reactor under commercially-relevant conditions. Experimental results in terms of reactor bed temperature, H2 consumption, aromatics and diesel yields have been analyzed and compared to the current commercial hydrotreater load and catalyst supplier forecasts for the studied configurations. Results show excellent performances of reactivated catalysts and a strong effect of the NiMo layer in the case of the stacked configuration. In a pure CoMo configuration, up to 75% reactor volume of reactivated catalyst could be utilized without impacting the product quality and cycle length, compared to a full fresh CoMo catalyst load. The full reactivated stacked configuration performed even better than the full fresh CoMo catalyst, without impacting product quality and diesel yield. Potential effect of the reactivated catalysts on the reaction selectivity and the role of the NiMo layer in the stacked configuration are discussed. Pilot-plant experimental data were in strong accordance with catalyst supplier commercial forecasts, emphasizing the quality of the pilot-plant study. Implementation of one of the studied configuration by the refinery could lead to between 30% and 55% savings on the cost of catalyst for the next load.ISSN:1294-4475ISSN:0020-2274ISSN:1953-818

Maximizing utilization of reactivated and left-over catalysts in heavy gas oil hydrotreater: A case study of ADNOC Refining

Recently, ADNOC Refining Research Center (ARRC) has studied the possibility to maximize the reutilization of left-overs and reactivated hydrodesulfurization catalysts for one of its hydrotreater producing Ultra Low Sulfur Diesel (ULSD) from Heavy Gas Oil (HGO). Based on the refinery inventory, several catalyst configurations composed of different amounts of reactivated and fresh CoMo catalyst, including a full reactivated configuration having a stacked CoMo/NiMo/CoMo combination (50/25/25), have been tested in a pilot-plant reactor under commercially-relevant conditions. Experimental results in terms of reactor bed temperature, H2 consumption, aromatics and diesel yields have been analyzed and compared to the current commercial hydrotreater load and catalyst supplier forecasts for the studied configurations. Results show excellent performances of reactivated catalysts and a strong effect of the NiMo layer in the case of the stacked configuration. In a pure CoMo configuration, up to 75% reactor volume of reactivated catalyst could be utilized without impacting the product quality and cycle length, compared to a full fresh CoMo catalyst load. The full reactivated stacked configuration performed even better than the full fresh CoMo catalyst, without impacting product quality and diesel yield. Potential effect of the reactivated catalysts on the reaction selectivity and the role of the NiMo layer in the stacked configuration are discussed. Pilot-plant experimental data were in strong accordance with catalyst supplier commercial forecasts, emphasizing the quality of the pilot-plant study. Implementation of one of the studied configuration by the refinery could lead to between 30% and 55% savings on the cost of catalyst for the next load