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Instruments / Technical Area	Publication Details	Published
B18-Core EXAFS	Catalytic decomposition of N2O over Cu–Al–Ox mixed metal oxides Magdalena Jablonska , Miren Agote Arán , Andrew M. Beale , Kinga Góra-Marek , Gérard Delahay , Carolina Petitto , Kateřina Pacultová , Regina Palkovits Rsc Advances 9, 3979 - 3986 DOI: 10.1039/C8RA10509J Diamond Proposal Number(s): [14834] Open Access Show Abstract ▼ Abstract: Cu–Al–Ox mixed metal oxides with intended molar ratios of Cu/Al = 85/15, 78/22, 75/25, 60/30, were prepared by thermal decomposition of precursors at 600 °C and tested for the decomposition of nitrous oxide (deN2O). Techniques such as XRD, ICP-MS, N2 physisorption, O2-TPD, H2-TPR, in situ FT-IR and XAFS were used to characterize the obtained materials. Physico-chemical characterization revealed the formation of mixed metal oxides characterized by different specific surface area and thus, different surface oxygen default sites. The O2-TPD results gained for Cu–Al–Ox mixed metal oxides conform closely to the catalytic reaction data. In situ FT-IR studies allowed detecting the form of Cu+⋯N2 complexes due to the adsorption of nitrogen, i.e. the product in the reaction between N2O and copper lattice oxygen. On the other hand, mostly nitrate species and NO were detected but those species were attributed to the residue from catalyst synthesis.	Jan 2019
B18-Core EXAFS	Understanding the origins of N2O decomposition activity in Mn(Fe)CoAlO hydrotalcite derived mixed metal oxides Magdalena Jablonska , Miren Agote-Aran , Andrew M. Beale , Gérard Delahay , Carolina Petitto , Marek Nocuń , Regina Palkovits Applied Catalysis B: Environmental DOI: 10.1016/j.apcatb.2018.10.010 Diamond Proposal Number(s): [14834] Show Abstract ▼ Abstract: The catalytic decomposition of N2O was studied over a series of calcined Mn(Fe)CoAl hydrotalcite-like compounds. The precursors were prepared by coprecipitation and characterized by XRD and TGA. The mixed metal oxides derived after calcination at 600 °C were characterized by XRD, N2 adsorption, H2-TPR and XPS. Moreover, in situ XAFS measurements over selected mixed metal oxides were performed. Such investigations under relevant reaction conditions are rare, while a comprehensive understanding of the involved active species may facilitate a knowledge-based catalyst optimization. The activity of the CoAlOx (Co/Al = 3/1, mol.%) catalyst varied depending on the loading of Mn or Fe (0.0575, 0.0821, 0.1150, 0.1725, 0.2300, mol.%). In the investigated series, Mn0.1725Co3AlOx reached the highest activity with T50 of about 305 and 376 °C under N2O/N2 and N2O,NO,O2/N2 feed, respectively. In situ X-ray absorption experiments over Mn0.1725Co3AlOx suggested that MnxCoyO4 spinels undergo reduction to CoO and MnO upon heating up to 600 °C in He. Under N2O/He conditions, initial reoxidation of cobalt species began at 350 °C. The lower activity obtained for Fe0.1725Co3AlOx is explained by the fact that the majority of Fe was not incorporated into the Co3O4 structure but instead formed less reactive iron oxide clusters.	Oct 2018
B18-Core EXAFS	Comparison of Cu-Mg-Al-Ox and Cu/Al2O3 in selective catalytic oxidation of ammonia (NH3-SCO) Magdalena Jablonska , Bernd Wolkenar , Andrew M. Beale , Stefan Pischinger , Regina Palkovits Catalysis Communications 110, 5 - 9 DOI: 10.1016/j.catcom.2018.03.003 Diamond Proposal Number(s): [14834] Show Abstract ▼ Abstract: Copper-based materials are promising catalysts in the selective catalytic oxidation of ammonia into nitrogen and water vapour (NH3-SCO). Investigations under applied reaction conditions over such materials seem to be rare and a comprehensive understanding of the involved active copper oxide species could facilitate a knowledge-based catalyst optimization. In the present work, Cu-Mg-Al-Ox mixed metal oxides and Cu/Al2O3 active catalysts in NH3-SCO were investigated under NH3/O2/CO2/H2O/N2 reaction conditions. Powder XRD, BET, NH3-TPD, H2-TPR and XAFS methods were used to characterize Cu-Mg-Al-Ox (Cu/Mg/Al = 8/63/29, mol%) and 10 wt% Cu/Al2O3. Cu-Mg-Al-Ox hydrotalcite derived mixed metal oxides were obtained by coprecipitation, while Cu/Al2O3 was prepared by incipient wetness impregnation. A highly dispersed copper oxide species formed on Cu-Mg-Al-Ox, while a mixture of highly dispersed (CuOx) and bulk copper oxide species (CuO and CuAl2O4) formed on Cu/Al2O3. The comparison of Cu-Mg-Al-Ox and Cu/Al2O3 in NH3-SCO provided good insight into the nature of the active species present in both copper-based catalysts. It was found that highly dispersed easily reducible copper oxide species and bulk copper oxide species appear as active species under NH3/O2/N2 and NH3/O2/CO2/H2O/N2 reaction conditions, respectively.	May 2018
B18-Core EXAFS	Ag-Cu based catalysts for the selective ammonia oxidation into nitrogen and water vapour Magdalena Jablonska , Andrew Beale , Marek Nocun , Regina Palkovits Applied Catalysis B: Environmental DOI: 10.1016/j.apcatb.2018.03.029 Diamond Proposal Number(s): [14834] Show Abstract ▼ Abstract: XRD, BET, H2-TPR, UV-vis-DRS, XPS and XAFS were used to characterize a series of Ag and/or Cu – Ag (1-5%), Cu (10-15%) or Ag-Cu (1-1, 1-10, 1.5-10, 5-5% of metal) – supported on γ-Al2O3. Correlation between physicochemical properties, catalytic activity and selectivity in NH3-SCO were thoroughly investigated. Silver species mainly in the form of Ag2O on the Ag/Al2O3 catalysts led to enhanced activity together with drop in N2 selectivity with increasing silver loading up to 5%. A mixture of CuO and CuAl2O4 formed on the Cu/Al2O3 catalysts. Easily reducible highly dispersed CuOx promoted the activity of the catalysts, while bulk CuOx and CuAl2O4 decreased N2 selectivity up to 500 °C. The activity of all Cu-containing materials was inferior to Ag-containing ones. Thus, the gap between the high conversion temperature over Cu/Al2O3 and low N2 selectivity over Ag/Al2O3 was bridged by applying the Ag-Cu/Al2O3 catalysts, with the optimum loading of 1.5 and 10 wt.% for silver and copper, respectively. NH3-TPD, NH3-TPSR and in situ FTIR were used to determine the in situ selective catalytic reduction (i-SCR) mechanism over 1.5% Ag/Al2O3, 10% Cu/Al2O3 and 1.5% Ag-10% Cu/Al2O3 respectively. The i-SCR mechanism involved the partial oxidation of NH3 into NOx species, along with adsorbed NOx species interacting with adsorbed ammonia (NHx species) and being reduced to reaction products.	Mar 2018

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