@article { ISI:000227016500007, title = {In situ XPS investigations of Cu1-xNixZnAl-mixed metal oxide catalysts used in the oxidative steam reforming of bio-ethanol}, journal = {Applied Catalysis B - Environmental}, volume = {55}, number = {4}, year = {2005}, month = {FEB}, pages = {287-299}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A series of CuNiZnAl-multicomponent mixed metal oxide catalysts with various Cu/Ni ratios were prepared by the thermal decomposition of Cu1-xNixZnAl-hydrotalcite-like precursors and tested for oxidative steam reforming of bio-ethanol. Dehydrogenation of EtOH to CH3CHO is favored by Cu-rich catalyst. Introduction of Ni leads to C-C bond rupture and producing CO, CO2 and CH4. H-2 yield (selectivity) varied between 2.6-3.0 mol/mol of ethanol converted (50-55\%) for all catalysts at 300 degreesC. The above catalysts were subjected to in situ XPS studies to understand the nature of active species involved in the catalytic reaction. Core level and valence band XPS as well as Auger electron spectroscopy revealed the existence of Cu2+, Ni2+ and Zn2+ ions on calcined materials. Upon in situ reduction at reactions temperatures, the Cu2+ was fully reduced to Cu-0. while Ni2+ and Zn2+ were partially reduced to Ni-0 and Zn-0, respectively. On reduction, the nature of ZnO on Cu-rich catalyst changes from crystalline to amorphous, relatively inert and highly stabilized electronically. Relative concentration of the Ni-0 and Zn-0 increases upon reduction with decreasing Cu-content. Valence band results demonstrated that the overlap between 3d bands of Cu and Ni was marginal on calcined materials, and no overlap due to metallic clusters formation after reduction. Nonetheless, the density of states at Fermi level increases dramatically for Ni-rich catalysts and likely this influences the product selectivity. (C) 2004 Elsevier B.V. All rights reserved.

}, keywords = {auger electron spectroscopy, Autothermal reforming, Bio-ethanol, copper oxide, fuel cell, Hydrogen, hydrotalcite, mixed metal oxides, nickel oxide, oxidative steam reforming, Steam reforming, XPS}, issn = {0926-3373}, doi = {10.1016/j.apcatb.2004.09.007}, author = {Velu, S. and Suzuki, K. and Vijayaraj, M. and Barman, S. and Gopinath, Chinnakonda S.} } @article { ISI:000348753400054, title = {Highly loaded well dispersed stable Ni species in NiXMg2AlOY nanocomposites: application to hydrogen production from bioethanol}, journal = {Applied Catalysis B-Environmental}, volume = {166}, year = {2015}, month = {MAY}, pages = {485-496}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Inexpensive NiXMg2AlOY nanocomposites with high Ni content (Ni wt\% \> 40\%) are developed as efficient catalysts for the sustainable hydrogen production from a mixture of ethanol and water at low temperature. The NiXMg2AlOY nanocomposites are composed of small and uniform nanoparticles (4-6 nm) of NiO, Ni-Mg-(Al)-O and/or MgO. The strong interactions existing between Ni2+ cations and Mg2+ and/or Al3+ cations either in the Ni-Mg-(Al)-O solid solution and/or at the interface of nanoparticles of NiO and/or Ni-Mg-(Al)-O make the catalyst highly active and stable. The behavior of the solids is analyzed in the presence of low and high concentrations of ethanol while maintaining a H2O/EtOH molar ratio of 3. The NiXMg2AlOY catalysts are shown to be efficient toward H-2 production between 250 and 650 degrees C. In the presence of low concentration of ethanol, on the highly loaded Ni compound (Ni12Mg2AlOY), total conversion of ethanol is obtained at 250 degrees C without formation of CO and carbon, and at 300 degrees C a H-2 yield of 3 mol moletEtOH(-1) is obtained without the formation of CO, exhibiting a remarkable stability with the time on stream even if some carbon is formed. In high concentration of ethanol, total conversion of ethanol is obtained at 450 degrees C on the highly loaded Ni compound (Ni12Mg2AlOY). In such conditions, a stable co-generation of carbon nanofibrous materials which amount increases with Ni content is also obtained. The catalytic stability is related to the type and morphology of the carbon species formed. The correlations among the catalyst properties, the catalytic performances and the characterizations are thoroughly discussed. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Ethanol, Hydrogen, Nanofibrous carbon, nickel oxide, Steam reforming}, issn = {0926-3373}, doi = {10.1016/j.apcatb.2014.11.052}, author = {Fang, Wenhao and Paul, Sebastien and Capron, Mickael and Biradar, Ankush V. and Shubhangi B. Umbarkar and Dongare, Mohan K. and Dumeignil, Franck and Jalowiecki-Duhamel, Louise} } @article { ISI:000367561500004, title = {p-type NiO hybrid visible photodetector}, journal = {ACS Applied Materials \& Interfaces}, volume = {7}, number = {50}, year = {2015}, month = {DEC}, pages = {27597-27601}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A novel hybrid visible-light photodetector was created using a planar p-type inorganic NiO layer in a junction with an organic electron acceptor layer. The effect of different oxygen pressures on formation of the NiO layer by pulsed laser deposition shows that higher pressure increases the charge carrier density of the film and lowers the dark current in the device. The addition of a monolayer of small molecules containing conjugated pi systems and carboxyl groups at the device interface was also investigated and with correct alignment of the energy levels improves the device performance with respect to the quantum efficiency, responsivity, and photogeneration. The thickness of the Organic layer was also optimized for the device, giving a responsivity of 1.54 X 10(-2) A W-1 in 460 nm light.

}, keywords = {nickel oxide, organic, oxygen vacancies, photodetector, pulsed laser deposition, surface modifier}, issn = {1944-8244}, doi = {10.1021/acsami.5b09291}, author = {Mallows, John and Planells, Miguel and Thakare, Vishal and Bhosale, Reshma and Ogale, Satishchandra and Robertson, Neil} }