Sökning: "Cu-CHA"

Visar resultat 1 - 5 av 10 avhandlingar innehållade ordet Cu-CHA.

  1. 1. Reaction kinetics of NH3-SCR over Cu-CHA from first principles

    Författare :Yingxin Feng; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; density functional theory; ammonia assisted selective catalytic reduction; Cu-CHA; microkinetic modeling; Catalysis;

    Sammanfattning : Ammonia assisted selective catalytic reduction (NH3-SCR) is a leading technology that is used for NOx reduction to N2 and H2O in oxygen excess. Thanks to its high activity, high selectivity, and durability, Cu-CHA is commercialized as an NH3-SCR catalyst. LÄS MER

  3. 2. Reaction kinetics of NH3-SCR over Cu-CHA from first principles

    Författare :Yingxin Feng; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Catalysis; microkinetic modeling; density functional theory; Cu-CHA; ammonia assisted selective catalytic reduction;

    Sammanfattning : Ammonia-assisted selective catalytic reduction (NH3-SCR) is an advanced technology to reduce nitrogen oxide (NOx) emissions from lean-burn engines. NH3 is added to the exhaust gas and reacts selectively with NOx, forming N2 and H2O. LÄS MER

  4. 3. Dynamics and Reactivity of Cu-species in Cu-CHA for NH3-SCR

    Författare :Joachim Bjerregaard; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Machine Learning Force Field; Diffusion; Cu-CHA; NH3-SCR; DFT; Sulfur Deactivation;

    Sammanfattning : Copper exchanged chabazite (Cu-CHA) is a state-of-the-art catalyst for deNOx via ammonia assisted selective catalytic reduction (NH3-SCR) in lean burn engines, owing to its good low-temperature activity, and high hydrothermal stability. One challenge for Cu-CHA is, however, the sensitivity to sulfur species, which are present in the exhaust gas. LÄS MER

  5. 4. On the reaction mechanism for selective catalytic reduction of NOx by NH3 over Cu-zeolites

    Författare :Lin Chen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; DFT; O2-activation; Cu-SSZ-13; NH3-SCR; Cu-CHA; Al-distribution;

    Sammanfattning : Nitrogen oxides (NOx) are major pollutants from combustion processes, being corrosive and hazardous to human health. The main technology for exhaust aftertreatment of NOx emitted from diesel engines is selective catalytic reduction with ammonia as reducing agent (NH3-SCR). LÄS MER

  7. 5. Reactions on nanostructured and microporous surfaces

    Författare :Anna Clemens; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Cu-CHA; XRD; solid-state ion-exchange; materials characterisation; electron microscopy; NH3-SCR; zeolites; catalysis; nanostructured graphite; Water ice; DRIFTS; XPS; NOx reduction; Cu-SSZ-13; temperature programmed desorption; ultra-high vacuum; intercalation; UV-Vis spectroscopy;

    Sammanfattning : Interactions between surfaces and molecules play a central role in various fields where catalysis is one example. In order to understand different surface processes, physicochemical characterisation of the surface materials and molecules is required. LÄS MER