Ni物种形态对Ni/AC催化剂低温脱硫性能的影响(英文)

Influence of Ni Species of Ni/AC Catalyst on Its Desulfurization Performance at Low Temperature

采用过量浸渍法制备了Ni/AC催化剂,考察了不同焙烧温度对Ni/AC脱硫活性的影响,并通过X射线衍射和X射线光电子能谱对催化剂进行了表征,研究了经不同温度焙烧后的催化剂上的Ni物种形态及其对催化剂性能的影响.结果表明,经400°C焙烧后的催化剂中Ni物种为Ni2O3,550°C焙烧后出现了NiO物种,800°C焙烧后Ni物种变为NiO和Ni共存,而1000°C焙烧后只存在单质Ni.这说明不同温度焙烧后的催化剂中Ni形成了不同的化学形态.脱硫活性的测试结果表明,经550°C和800°C焙烧后的催化剂表现出较好的脱硫活性,而400°C焙烧的催化剂脱硫活性最差.这说明Ni在催化剂上的不同化学形态是造成脱硫效果差异的主要原因,而NiO是Ni/AC催化剂脱硫的主要活性物相.

A series of Ni/AC catalyst samples were prepared by excessive impregnation, and the desulfurization activity of Ni/AC calcined at different temperatures was investigated. The Ni species on the Ni/AC catalyst calcined at different temperatures were studied by X-ray dif- fraction and X-ray photoelectron spectroscopy. The characterization results showed that the Ni species on the catalyst calcined at 400 °C is Ni2O3. After calcination at 550 °C, NiO species is formed on the activated carbon. NiO and Ni coexist on the Ni/AC catalyst calcined at 800 °C, and only pure Ni species is observed after calcination at 1 000 °C. This suggested that Ni can form different chemical states on the Ni/AC catalyst calcined at different temperatures. The desulfurization test results showed that the catalysts calcined at 550 and 800 °C exhibit good desulfurization activity, whereas the catalyst calcined at 400 °C has poor activity, indicating that different chemical states of Ni on the Ni/AC catalyst show different desulfurization performance, and NiO is the main active phase of the Ni/AC catalyst.