Uniformity of supported CuO from rate of reduction with hydrogen*1

Voge, H. H.

doi:10.1016/0021-9517(62)90021-0

Cited by 34 publications

(5 citation statements)

References 10 publications

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“…1971; Verhoeven and Delmon, 1966) have shown that small quantities of platinum or palladium can effectively promote the hydrogen reduction of aluminasupported nickel oxide which is otherwise very difficult to reduce (Hill and Selwood, 1948). Figure 3A showed that CU-AI2O3 which is readily reducible (Voge and Atkins, 1962) removes NO at low temperature. This suggests that nickel, when it is rendered reducible by platinum or palladium, resembles copper in the catalytic reduction of nitric oxide.…”

Section: Resultsmentioning

confidence: 98%

Ammonia intermediacy as a basis for catalyst selection for nitric oxide reduction

Klimisch¹,

Taylor²

1973

Environ. Sci. Technol.

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Section: Resultsmentioning

confidence: 98%

Ammonia intermediacy as a basis for catalyst selection for nitric oxide reduction

Klimisch¹,

Taylor²

1973

Environ. Sci. Technol.

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“…Initially, there is a phase of accelerating reduction. Such an accelerated the reduction is indicative of an autocatalytic process, 52,53 although a particle size dependence of the reduction process may also contribute to the observed behavior. In this regime, the formation of copper(I) oxide, as a short-lived intermediate, occurs at both pressures.…”

Section: Dynamic Reduction Behavior Of Cza At Different Pressuresmentioning

confidence: 92%

Following the structure of copper-zinc-alumina across the pressure gap in carbon dioxide hydrogenation

et al. 2021

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Copper-zinc-alumina catalysts are the industrially-used formulation for methanol synthesis from carbon monoxide and carbon dioxide containing feedstock. Its high performance stems from synergies that develop between its components. This important catalytic system has been investigated with a myriad of approaches, however, no comprehensive agreement has emerged as to the fundamental source of its high activity. One potential source of the disagreements is the considerable variation in pressure used in studies to understand a process that is industrially performed at pressures above 20 bar. Here, by systematically studying the catalyst state during temperature-programmed reduction and under carbon dioxide hydrogenation with in situ and operando X-ray absorption spectroscopy over four orders of magnitude in pressure, we show how the state and evolution of the catalyst is defined by its environment. Especially below 1 bar, the structure of the catalyst shows a strong pressure dependence. As pressure gaps are a general problem in catalysis, these observations have wide-ranging ramifications.The improvement of heterogeneous catalysts is central to a sustainable development of energy conversion and the production of chemicals. Historically, such development relied heavily on trial-and-error based research. More recently, advances in characterization methods allowed the study of catalysts under pretreatment and catalytic conditions, thus in situ and operando. This has permitted the possibility to derive fundamental understanding of the state of the catalyst whilst it is actually working 1 . Ideally, a detailed comprehension of the reaction mechanisms of the desired catalytic reaction emerges. Many of these methods, such as electron microscopy and X-ray photoelectron spectroscopy, remain limited in their routine application to pressure regimes in the millibar range [2][3][4][5] ; others, however, such as X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD), suffer no

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“…Catalyst Composition and Attrition. Based on the findings (Voge and Atkins, 1962) that the state of copper oxide affected its ease of reduction, it was hypothesized that dispersion of the copper phase might influence susceptibility to attrition. Accordingly, extensive studies were made to investigate this parameter.…”

Section: Resultsmentioning

confidence: 99%

Copper-Based Auto Exhaust Oxidation Catalysts. Deactivation and Physical Attrition

Roth¹

1971

Product R&D

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untreated catalyst. The resistance of zeolites to attack by (or dissolution in) aqueous acids follows the same order.At lower temperatures (<210°C) the activity of NaY for the decomposition of the secondary ester remained constant. Constant activities were observed for silica-aluminas with the normal ester at 190°C (Sanyal and Weller, 1971), but our sample of silica-alumina aged at 190°C in the decomposition of the secondary ester. The activity of AgY increased slowly with time in the decomposition of the secondary ester at 140-170°C. Apparently, the silver ion is reduced to metallic silver by the reactant or products, and the zeolite is transformed to the hydrogen form.

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Uniformity of supported CuO from rate of reduction with hydrogen*1

Cited by 34 publications

References 10 publications

Ammonia intermediacy as a basis for catalyst selection for nitric oxide reduction

Ammonia intermediacy as a basis for catalyst selection for nitric oxide reduction

Following the structure of copper-zinc-alumina across the pressure gap in carbon dioxide hydrogenation

Copper-Based Auto Exhaust Oxidation Catalysts. Deactivation and Physical Attrition

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