摘要
本文报道了一种适合催化研究的金属原位IR池.Pt分散在NH_4L沸石上呈缺电子性,在异丙醇分解反应中不显示脱氢活性,但通过加氢抗结炭作用保护着沸石上的酸位,从而增强了NH_4L沸石的酸性催化作用.负载在碱性KL沸石上的Pt呈富电子性,在反应中极易被噻吩中毒、(Pt/KL+NH_4L)混合样品在预处理和反应的过程中,Pt从KL向NH_4L沸石上迁移,导致其催化性能相似于Pt/NH_4L.实验证明:Pt与L沸石载体之间存在着明显的相互作用.由于Pt易给出电子而不易接受电子,因此与酸位的相互作用强于与碱位的相互作用.
A new in situ IR cell- which was made of metal and suitable for catalysis research, was reported in this paper. The Pt dispersed on acidic NH4L zeolite exhibited 'electronic deficiency' and did not show bvious dehydrogenation activity in isopropanol decomposition reaction. But enhanced the conversion of isopropanol to form H2O and propene through the protection for the acid sites on zeolite against deactivation by carbonaceous overlayers. Pt on KL basic zeolite, however, exhibited some electron rich and high dehydrogenation activity in isopropanol decomposition. Beside, Pt / KL was very sensitive to thiophene poison in reactions. During the process of pretreatment and reaction, the Pt on the mixture of (Pt / KL+NH4L) migrated from KL to NH4L and resulting in that the catalytic properties of the mixture similar as that of Pt / NH4L in decomposition of isopropanol. It was proved that there was an obvious interaction between Pt and L zeolites. The Pt supported was easier to become 'electronic defi ciency' than to be 'electronic rich', which meant that the interaction of Pt with acidic sites was stronger than that of Pt with basic sites, which meant that, because of the metallicity of Pt which can be electronic donor easily but difficult to be the electronic accepter.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1995年第2期111-115,共5页
Acta Chimica Sinica
基金
国家教委优秀青年教师基金
国家自然科学基金资助项目
