MgO负载Ni催化剂催化水蒸气重整生物醇制氢

发布时间：2018-05-31 22:30

本文选题：MgO + Ni基催化剂　；参考：《哈尔滨师范大学》2015年硕士论文

【摘要】：本文进行以NiO-MgO固溶体为催化剂前体,还原后得到Ni负载在MgO上的催化剂,进行催化水蒸气重整丁醇制氢的研究。运用共沉淀法制备出NiO-MgO固溶体,用浸渍制备出NiO/MgO和NiO/MgO-m(MgO-m为介孔氧化镁)固溶体。在650 oC下,经10%H2/Ar还原,被还原1 h后得活性组分为金属Ni的Ni/MgO催化剂。应用XRD,N2吸附/脱附对固溶体进行表征。还原后所得Ni/NiO-MgO,Ni/MgO,Ni/Al2O3及Ni/MgO-m四种催化剂,并在固定床上,进行水蒸气重整丁醇制氢的研究。应用XRD,程序升温氧化(TPO)及程序升温加氢(TPH)的技术,对催化剂前体和催化剂进行表征。表征结果表明,以介孔的氧化镁(MgO-m)为载体浸渍在Ni(NO3)2水溶液中,制备出的NiO/MgO-m固溶体,其具有较好的介孔结构,比表面积为68.12 m2/g,平均孔径为4.20 nm,是普通MgO浸渍制备的NiO/MgO固溶体比表面(21.85 m2/g)的3.11倍。水蒸气重整丁醇催化制氢结果表明,在所制备的催化剂中,以介孔MgO为载体的Ni/MgO-m的催化剂,催化活性及稳定性最高。在T=550 oC,LHSV=8 h-1,CC4H9OH=4.89 wt%条件下,丁醇转化率为92.4%,氢气选择性是76.7%,氢气的产率为11.07 mol/mol。在开始反应的20 h之内,Ni/MgO-m催化剂趋于稳定,氢气选择性及产率保持在80.0%和6.2 mol/mol左右。这主要是由于,介孔MgO具有高的比表面积,有利于活性组分Ni的分散。且介孔MgO还具有大的孔径,益于反应物及产物的传输。因此,介孔催化剂Ni/MgO-m表现出了较高催化活性及稳定性。催化剂表征结果表明,作为活性组分的金属Ni的,没有随反应时间发生变化,由此使得Ni/MgO-m催化剂具有很高的稳定性,积碳表征表明,催化剂上的积碳组成为石墨C,CxHy或Cx HyOz。综上所述,利用水蒸气催化重整丁醇制氢,所制备的催化剂里面,介孔MgO-m浸渍Ni(NO3)2制备的催化剂与其它催化剂比较,有最高的催化活性及稳定性。
[Abstract]:In this paper, the catalyst supported on MgO was obtained by using NiO-MgO solid solution as catalyst precursor after reduction, and the catalytic steam reforming of butanol to hydrogen was studied. NiO-MgO solid solution was prepared by coprecipitation and NiO/MgO and NiO/MgO-m(MgO-m were prepared by impregnation. After being reduced by 10%H2/Ar at 650oC for 1 h, the active component was obtained as Ni Ni/MgO catalyst. The solid solution was characterized by XRDN _ 2 adsorption / desorption. After reduction, four kinds of Ni / NiO-MgO / Ni / MgO _ 2O _ 3 / Al _ 2O _ 3 and Ni/MgO-m catalysts were prepared and steam reforming to produce hydrogen from butanol was carried out in a fixed bed. The precursor and catalyst were characterized by XRD, TPO and TPH. The characterization results show that the NiO/MgO-m solid solution prepared by impregnating the mesoporous MgO-m in Ni(NO3)2 aqueous solution has a good mesoporous structure. The specific surface area is 68.12 m2 / g and the average pore size is 4.20 nm, which is 3.11 times higher than that of the NiO/MgO solid solution prepared by ordinary MgO impregnation (21.85 m2 / g). The results showed that the catalytic activity and stability of the catalyst of Ni/MgO-m supported on mesoporous MgO was the highest. The conversion of butanol was 92.4w%, the selectivity of hydrogen was 76.7mol / mol, and the yield of hydrogen was 11.07 mol / mol under the condition of TG550oC LHSVO 8h-1h -1 CC4H9OHH 4.89 wt%, the conversion of butanol was 92.4wt%, the selectivity of hydrogen was 76.7mol / mol. The Ni / MgO-m catalyst tends to be stable within 20 h after the initial reaction, and the selectivity and yield of hydrogen are about 80.0% and 6.2 mol/mol. This is mainly due to the high specific surface area of mesoporous MgO, which is conducive to the dispersion of active component Ni. The mesoporous MgO also has large pore size, which is beneficial to the transport of reactants and products. Therefore, the mesoporous catalyst Ni/MgO-m showed high catalytic activity and stability. The results of catalyst characterization showed that Ni, as an active component, did not change with the reaction time, which made the Ni/MgO-m catalyst have a high stability. The carbon deposition on the catalyst indicated that the carbon composition of the catalyst was graphite CXHy or CX HyOz. To sum up, the catalyst prepared by steam catalytic reforming of butanol to produce hydrogen has the highest catalytic activity and stability compared with other catalysts prepared by mesoporous MgO-m impregnated Ni(NO3)2.
【学位授予单位】：哈尔滨师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;TQ116.2

【相似文献】