Carbon deposition on borated alumina supported nano-sized Ni catalysts for dry reforming of CH4
Carbon deposition on borated alumina supported nano-sized Ni catalysts for dry reforming of CH4
复制标题
DOI：
10.1016/j.nanoen.2012.07.011
复制
发表时间：
2012-09-01
期刊：
影响因子：
17.6
通讯作者：
Kawi, Sibudjing
中科院分区：
文献类型：
--
作者：
Ni, Jun;Chen, Luwei;Kawi, Sibudjing
采用XRD、H-2-TPR、CO2-TPD、NH3-TPD、原位DRIFTS等方法对B2O3负荷量为0、1、5、10 wt%的硼化氧化铝负载5 wt% Ni催化剂进行了表征，并对甲烷干重整进行了评价。B2O3的加入对催化剂的活性和稳定性有显著影响。当B2O3的负载从0 wt%增加到10 wt%时，Ni的粒径从5.8 nm增加到9.1 nm。在动力学控制温度区（700℃），镍颗粒尺寸与催化剂活性/稳定性之间没有线性关系。在1 wt%和10 wt% B2O3负载的Ni催化剂上，强Lewis酸位点的形成导致了严重的碳沉积，从而降低了催化活性和稳定性。在5 wt% B2O3促进的Ni催化剂上，弱Lewis酸位点和O-H基团的形成显著促进了碳的去除，提高了催化剂的稳定性。提出了甲烷在硼化氧化铝负载的Ni催化剂上干重整反应机理，特别强调了OH基团对抑制碳生成的促进作用。(C) 2012 Elsevier Ltd.版权所有。
Borated alumina supported 5 wt% Ni catalysts with B2O3 loading varying from 0 wt%, 1 wt%, 5 wt% to 10 wt% were prepared and characterized by XRD, H-2-TPR, CO2-TPD, NH3-TPD, in situ DRIFTS study, and evaluated for dry reforming of methane. The addition of B2O3 influences the activity and stability of the catalysts significantly. Ni particle size increases from 5.8 to 9.1 nm with increasing the B2O3 loading from 0 to 10 wt%. In the kinetic control temperature region (700 degrees C) there is no linear relationship between the Ni particle size and the catalyst activity/stability. The formation of strong Lewis acid sites causes severe carbon deposition on 1 wt% and 10 wt% B2O3 loaded Ni catalysts, hence decreasing catalytic activity and stability. The formation of weak Lewis acid sites and O-H groups on 5 wt% B2O3 promoted Ni catalyst is found to significantly facilitate carbon removal and improve the stability of the catalysts. The reaction mechanism of dry reforming of methane over borated-alumina supported Ni catalysts is proposed, especially the promotional effect of OH groups on the suppression of carbon formation being emphasized. (C) 2012 Elsevier Ltd. All rights reserved.