NiWO4 nanoparticles: a promising catalyst for hydrodesulfurization

Abstract

NiWO(4) nanoparticles have been facilely synthesized by a hydrothermal approach, and used as a catalyst for the hydrodesulfurization of thiophene and its derivative 4,6-dimethyldibenzothiophene, showing a significantly higher activity than commercial NiW/Al(2)O(3).

Synchrotron-based far-infrared spectroscopy of nickel tungstate

“…Recent interests on NiWO 4 have been stimulated by its applications as a catalyst [9,10], in supercapacitors [10,11] and light-controlled bipolar resistive switching devices [12] as well as by numerous possibilities to produce it in nanostructured form [13][14][15][16][17][18][19][20].…”

Co‐liquefaction of lignite and biomass over Ni7W3 and Ni3W7 catalysts

“… At the same time, the original Ni 3 W 7 catalyst exhibits some scattered small peaks at 2θ = 13.3, 30.2, 35.9, 40.7, 49.3, and 54.7, which correspond to the NiWO 4. In additional to the peaks from WO 3 and NiWO 4 , the original Ni 3 W 7 catalyst exhibits some new peaks at 2θ = 62.1, 74.8, and 78.8, which correspond to the NiO . Furthermore, the original Ni 3 W 7 catalyst exhibits two strong peaks at 2θ = 36.5 and 42.6, which also correspond to the NiWO 4.…”

“…Similar to H 2 ‐reduced Ni 3 W 7 , the H 2 ‐reduced Ni 7 W 3 catalyst has the same Ni,W and NiW species but with different peak intensity. Furthermore, the peaks at 2θ = 75.4 and 78.1 for both H 2 ‐reduced Ni 3 W 7 and H 2 ‐reduced Ni 7 W 3 can be attributed to reduced Ni,W species . After H 2 ‐reduction, Ni is easily reduced in the form of metal, but very small amounts of W are reduced in the metal form.…”

“…Furthermore, the original Ni 3 W 7 catalyst exhibits two strong peaks at 2θ = 36.5 and 42.6, which also correspond to the NiWO 4. During the calcination of NiW materials, WO 3 was formed from the decomposition of ammonium tungstate. Small amounts of Ni tend to combine with W to form NiWO 4 .…”

“…Only a small amount of broad peaks at 2θ = 31–34 can be found for the H 2 ‐reduced Ni 3 W 7 catalyst, which might be caused by the remaining non‐reduced WO 3 species. The newly formed peaks on the H 2 ‐reduced Ni 3 W 7 catalyst are depicted below: (1) the peaks at 2θ = 43.0, 52.4, and 77.9 are attributed to Ni(111), Ni(220), and Ni(220); (2) the peaks at 2θ = 40.1, 59.3, and 74.5 are attributed to the reduced W; (3) the peaks at 2θ = 43.5, 50.6, and/or 74.2 should be attributed to the reduced NiW species; and (4) the sharp peaks at 2θ = 22.7, 24.9, 35.5, and 65 might be attributed to the newly formed bulk NiWO 4 species …”