Ni@SiO_(2)核壳型催化剂上孔调控对甲烷干重整催化性能的影响  

Effects of pore modulation on catalytic performance of Ni@SiO_(2) core-shell catalysts for methane dry reforming

作　　者：冯文磊 杨文师 陈健勇[1] 王超[1] 陈颖 罗向龙[1] FENG Wenlei;YANG Wenshi;CHEN Jianyong;WANG Chao;CHEN Ying;LUO Xianglong(School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,Guangdong,China)

机构地区：[1]广东工业大学材料与能源学院,广东广州510006

出　　处：《低碳化学与化工》2024年第6期9-16,44,共9页Low-Carbon Chemistry and Chemical Engineering

基　　金：广东省基础与应用基础研究基金自然科学基金面上项目(2022A1515012035)。

摘　　要：采用油包水微乳液法制备了Ni@SiO_(2)核壳型催化剂,并添加梯度物质的量的十六烷基三甲基溴化铵(C_(16)TAB)进行后处理,制备了具有不同多孔结构的Ni@SiO_(2)-xC_(16)系列催化剂。结合N_(2)吸/脱附、XRD、TEM、H_(2)-TPR、XPS和Raman光谱等表征方法对催化剂进行了分析,探究了Ni@SiO_(2)-xC_(16)外壳上孔结构对催化剂活性、稳定性以及抗积炭性能的影响。结果表明,Ni@SiO_(2)-xC_(16)具有更大的比表面积和更丰富的孔结构,有助于提高Ni颗粒的分散度和限制Ni颗粒尺寸小于5 nm,并强化Ni颗粒与载体的相互作用。在50 h的稳定性测试中,Ni@SiO_(2)的初始CH_(4)转化率低(68.5%)且稳定性弱,而经过C_(16)TAB后处理的Ni@SiO_(2)-2C_(16)和Ni@SiO_(2)-3C_(16)则具有高初始CH4转化率(均约84.1%)及高稳定性,产物中n(H_(2))/n(CO)超过0.97,且几乎没有发生失活。经进一步研究发现,Ni@SiO_(2)-xC_(16)中碳物种的类型发生改变,由大量难以消除的石墨碳转化为少量容易清除的无序碳,因此,Ni@SiO_(2)-xC_(16)的抗积炭与抗烧结性能得到了提升。Ni@SiO_(2) core-shell catalysts were prepared by oil-in-water microemulsion method.Adding a gradient amount of substance of cetyltrimethylammonium bromide(C_(16)TAB)for post-treatments,Ni@SiO_(2)-xC_(16) catalysts with distinct porous structures were prepared.By characterization techniques including N_(2) adsorption/desorption,XRD,TEM,H_(2)-TPR,XPS and Raman spectroscopy,the catalysts were analyzed,and the effects of pore structures on Ni@SiO_(2)-xC_(16) shell on the activity,stability and anti-coking performance of catalysts were investigated.The results indicate that Ni@SiO_(2)-xC_(16) has a larger specific surface area and more abundant pore structures,which help to improve the dispersion of Ni particles,limit the size of Ni particles to less than 5 nm and strengthen the interaction between Ni particles and supports.In a 50 h stability test,Ni@SiO_(2) has a low initial CH4 conversion rate(68.5%)and weak stability,but after C_(16)TAB post-treatment,Ni@SiO_(2)-2C_(16) and Ni@SiO_(2)-3C_(16) show high initial CH_(4) conversion rates(both about 84.1%)and high stability,and n(H2)/n(CO)in products exceeds 0.97 and almost no deactivation occurred.After further study,it is found that the type of carbon species in Ni@SiO_(2)-xC_(16) changes from a large amount of graphite carbon that is difficult to eliminate to a small amount of disordered carbon that is easy to remove.Therefore,the performances of anti-coking and anti-sintering of Ni@SiO_(2)-xC_(16) are improved.

关 键 词：甲烷干重整 Ni@SiO_(2) 多孔结构 抗积炭性能 

分 类 号：TQ426[化学工程]