CAJ | 학술논문

在完全液相法研究发现的基础上，选用酸、碱性硅溶胶，制备Cu/Zn/Al/Si浆状催化剂，采用X射线衍射( XRD)、氢气程序升温还原( H2-TPR)、红外光谱分析( FT-IR)、氮气吸附、氨气程序升温脱附( NH3-TPD)、X射线光电子能谱( XPS)、透射电子显微镜( TEM)等对催化剂进行了表征。结果表明，两类硅溶胶引入Cu/Zn/Al催化体系后，与前驱体制备环境一致的酸性硅溶胶能显著提高催化剂的CO的转化率和二甲醚的选择性，最高分别可达65.38%和76.26%。酸性硅溶胶削弱了Cu与其他组分的相互作用力，催化剂表现为易于还原、晶粒度大，暴露出丰富的反应所需的Cu0活性晶面。此外，硅溶胶的酸碱性质还改变催化剂酸中心的强度和数量且使强、弱酸中心均向低温方向迁移，酸性硅胶制备的催化剂中弱酸中心数量多，进而提高了催化剂活性和二甲醚的选择性。大比表面积和介孔孔隙丰富的催化剂孔结构亦有利于催化剂活性和二甲醚选择性的提高。
재완전액상법연구발현적기출상，선용산、감성규용효，제비Cu/Zn/Al/Si장상최화제，채용X사선연사( XRD)、경기정서승온환원( H2-TPR)、홍외광보분석( FT-IR)、담기흡부、안기정서승온탈부( NH3-TPD)、X사선광전자능보( XPS)、투사전자현미경( TEM)등대최화제진행료표정。결과표명，량류규용효인입Cu/Zn/Al최화체계후，여전구체제비배경일치적산성규용효능현저제고최화제적CO적전화솔화이갑미적선택성，최고분별가체65.38%화76.26%。산성규용효삭약료Cu여기타조분적상호작용력，최화제표현위역우환원、정립도대，폭로출봉부적반응소수적Cu0활성정면。차외，규용효적산감성질환개변최화제산중심적강도화수량차사강、약산중심균향저온방향천이，산성규효제비적최화제중약산중심수량다，진이제고료최화제활성화이갑미적선택성。대비표면적화개공공극봉부적최화제공결구역유리우최화제활성화이갑미선택성적제고。
A series of Cu/Zn/Al/Si slurry catalysts were prepared by the complete liquid-phase technology with acid and alkaline silica sol in the paper. The catalysts are characterized by means of XRD, H2-TPR, FT-IR, BET, NH3-TPD, XPS and TEM. When the acid silica sol is added, which has the similar environment with the process of precursor preparation, the conversion of CO and selectivity of dimethyl ether reach maxiumum, being 65. 38% and 76. 26% respectively. The acid silica sol weakens the force between Cu and other components, resulting in the Cu component is easy to be reduced and more active lattice planes of Cu0 on the catalyst are exposed. The acid/alkaline properties of silica sol influence acid site strength and the number of acid sites of catalysts and make both strong acidic sites and the weak acidic sites migrate to lower temperature position. In DME synthesis reaction, it is found that the acid silica sol can increase the ratio of the weak acidic sites to the strong acidic sites on the catalysts, which promotes dehydration performance of methanol and the selectivity of DME. In addition, the catalysts with large specific surface area and mesoporous pore structure are favorable for the activity and selectivity of DME.