Oxidative Desulfurization Using in-Situ-Generated Peroxides in Diesel by Light Irradiation

Abstract

In this work, we explored a two-step oxidative desulfurization (ODS) approach using in-situ-generated peroxides in diesel by light irradiation. The supported catalysts were prepared by incipient wetness impregnation and characterized by N 2 adsorption test, X-ray diffraction, and X-ray photoelectron spectroscopy. Kinetic curves for peroxide generation by light irradiation and self-decomposition over a MoO 3 /SiO 2 catalyst were measured. Catalytic activities of the catalysts for ODS were tested. Results showed that (a) the efficiency of peroxide generation in diesel under a mercury lamp was much higher than that under a xenon lamp at the same light intensity and can be enhanced at a higher temperature, (b) with in-situ-generated peroxides in diesel by light irradiation, the ODS conversion of catalysts followed the order of MoO 3 /SiO 2 > V 2 O 5 /SiO 2 > WO 3 /SiO 2 and the conversion reached 75.6% using the MoO 3 /SiO 2 catalyst at the reaction temperature of 45 °C at the O/S ratio of 8, and (c) accompanying the main ODS reaction with hydroperoxides over the MoO 3 /SiO 2 catalyst in diesel, the competing side reaction of peroxide self-decomposition occurred and its kinetics increased dramatically with the reaction temperature. The overall ODS conversion may be affected by the diffusion of bulky refractory sulfur compounds in diesel on the catalyst, which can be enhanced by increasing the pore size of the MoO 3 /SiO 2 catalyst. The two-step oxidative desulfurization approach provides a viable path to achieve clean diesel effectively under mild conditions without using costly hydrogen.

Synthesis ofalpha-MoO$lt;inf$gt;3$lt;/inf$gt; Nanobelt and Its Photocatalytic Oxidative Desulfurization(Photo-ODS) Activity of Simulation Fuel

“…效果, 而被誉为绿色的脱硫工艺。近年来兴起的光 催化氧化脱硫 (Photo-Cat-ODS) 技术, 作为一种新 型的催化氧化脱硫技术倍受人们关注 [3][4][5][6][7][8][9][10] 。 MoO 3 作为一种 n 型宽带隙半导体材料, 以其独 特的结构和稳定的性能, 广泛应用于电极材料、催 化、光致变色、电致变色及其传感器等领域 [11][12][13][14][15] 。 在光催化领域, MoO 3 可同时响应紫外和可见光的光 学特性, 引起广泛关注 [16] 。Shao 等 [17] 制备了单晶结 构的一维(1D)α-MoO 3 纳米棒, 在可见光照射 1h 后, 该材料对罗丹明 B (RhB)降解率为 100%。 Kang 等 [16] 利用 1D MoO 3 纳米棒在紫外-可见光区成功地光催 化降解甲苯胺蓝和氯苯。Hou 等 [18] [19] ; 此外, α-MoO 3 纳 米具有较大的比表面积, 大的表面张力容易引起晶 格畸变, 导致晶格变小, 使其本征振动频率增大, 导 致光吸收带向短波方向偏移, 所以出现蓝移现象 [20] , 这与 XRD 分析结果一致。 根据半导体的带隙与带边吸收的关系: αhυ = (hυ-E g ) n [17,21]…”

One-pot photocatalysis-assisted adsorptive desulfurization of diesel over doped-TiO2under ambient conditions

“…The results suggest that the one-pot photocatalysis-assisted adsorption is not limited to photosensitive hydrocarbons-containing diesel, but is applicable to other fuel desulfurization processes as well. Compared to the previously reported two-step ODS approach, 27 oxygen generation as a rst-step is not required anymore in the study and excellent desulfurization performance was achieved. From the forgoing discussion, the photocatalysis-assisted adsorption mechanism can be summarized as follows: under UV light irradiation with the Ti 0.3 Si 0.7 O 2 photocatalyst, the organosulfur compounds were oxidized to the corresponding sulfoxides in air under ambient conditions.…”

Desulfurization of Spent Tire Pyrolysis Oil and Its Distillate via Combined Catalytic Oxidation using H2O2 with Formic Acid and Selective Adsorption over Al2O3

“…phosphotungstic acid) [18][19][20][21] and heterogeneous catalysts (e.g. transition metals based catalysts) [22][23][24][25][26] have been reported. Formic acid has been found to have a high catalytic activity in ODS of fuel oils 9,10,13,16 .…”