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The effect of distributor and channel positions on flowuniformityin a high-throughput reactor is studied using a COMSOL MULTIPHYSICS,CFD package. The best design is subsequently fabricated and evaluatedfor propane total oxidation reaction at low conversions. Comparisonof our design with a literature design is also presented. The resultsindicate that the conical distributor performs significantly betterin terms of flow uniformity as compared to the commonly used discshaped distributor. The flow uniformity is improved when the centralchannel is removed from the design, indicating that the channel arrangementalso affects the flow uniformity. The experimental results on flowuniformity are in good agreement with simulation. The deviation inconversion of propane from channel to channel is within experimentalerror, indicating that the reactor can reliably screen catalysts anddeliver kinetics. A half a dozen catalysts were tested for completepropane oxidation using the developed technology. [ABSTRACT FROM AUTHOR]

Abstract: Catalytic partial oxidation of isobutanol was investigated at various contact times and equivalence ratios for the purpose of H2 production. This reaction was studied using a γ-Al2O3 coated foam as a catalyst, as well as a similar foam with rhodium (Rh) added. The results show that little H2 is produced when the Rh is absent, whereas selectivities as high as 62.92% were achieved (80% is the theoretical maximum) with the noble metal present. The alumina catalyst also displays no complete combustion regime for fuel lean combustion; instead, olefins, carbon dioxide (CO2), and water are the dominant products at all equivalence ratios. Additional results from catalytic partial oxidation of isobutene suggest that isobutene could be an intermediate during catalytic partial oxidation of isobutanol. With approximately 8.25 W of isobutanol, 3.61 W of H2 can be attained with the Rh catalyst for use in small power devices, such as a proton exchange membrane fuel cell. The corresponding fuel-to-electricity efficiency was about 20.8%. [Copyright &y& Elsevier]

Despite significant research efforts, designing bimetallic catalysts rationally remains a challenging task. Herein, we combine the strengths of high-throughput experiments and DFT calculations synergistically to design new core-shell bimetallic catalysts. The total oxidation of propane is used as a probe, proof-of-concept reaction. The methodology is successful in designing three bimetallic catalysts. Of these catalysts, AgPd is cheaper, more active than the existing most active single-metal catalyst (Pt), and stable under the reaction conditions. Extended X-ray absorption fine structure characterization confirms the formation of a bimetallic alloy. This study provides a path forward for designing bimetallic catalysts rationally for vapor phase metal-catalyzed reactions. [ABSTRACT FROM AUTHOR]

The synthesis of hierarchical meso-/microporous zeolite materials with spatially controlled morphology, meso-/microporosity, and acidity is an expanding area of research interest for a wide range of applications. Here, we report a one-step dual template synthesis method for integration of 3-dimensional (3D) BEA nanosponge and ultra-thin 2D lamellar MFI into a new type of hierarchical meso-/microporous zeolite composite structures. Specifically, the 2D layered MFI nanosheets were laid over the surface of or interdigitated into the 3D BEA particles in the bulk BEA nanosponge-lamellar MFI (BBLM) zeolite structure, which generated a unique morphology of interconnected micropores and mesopores underneath the ‘skinning’ shell (∼3–10 nm) of MFI nanosheets. The BBLM zeolites have higher mesoporosity than either bare BEA or lamellar MFI zeolites. The micropore size decreases with increasing lamellar MFI component in the composite. The fraction of external acid sites of BBLM zeolite composite, represented by the percentage of active sites accessible to bulky organic base molecules, decreases with increasing MFI component. Additionally, the types of acid sites are diversified in the BBLM composites compared to either bare BEA or lamellar MFI zeolites. The catalysis tests using conversion of benzyl alcohol in mesitylene showed that BBLM zeolites had significant higher activity and durability than single zeolites or their physical mixture. The BBLM zeolite composite provides a good model catalyst with integrated 2D-3D structures and meso-/microporosity for studying a series of important catalytic reactions in hierarchical zeolites. The one-step dual template synthesis method described herein is versatile and facile, which may prove to be a general platform for hierarchical zeolite composite design at the unit-cell scales of zeolites and with potentially broader applicability to other porous materials. [ABSTRACT FROM AUTHOR]