Insight into the epitaxial encapsulation of Pd catalysts in an oriented metalloporphyrin network thin film for tandem catalysis

Abstract

A palladium catalyst (Pd-Cs) encapsulated metalloporphyrin network PIZA-1 thin film with bifunctional properties has been developed through a modified epitaxial layer-by-layer encapsulation approach. Combining the oxidation activity of Pd-Cs and the acetalization activity of the Lewis acidic sites in the PIZA-1 thin film, this bifunctional catalyst of the Pd-Cs@PIZA-1 thin film exhibits a good catalytic activity in a one-pot tandem oxidation-acetalization reaction. Furthermore, the surface components can be controlled by ending the top layer with different precursors in the thin film preparation procedures. The catalytic performances of these thin films with different surface composites were studied under the same conditions, which showed different reaction conversions. The result revealed that the surface component can influence the catalytic performance of the thin films. This epitaxial encapsulation offers a good understanding of the tandem catalysis for thin film materials and provides useful guidance to develop new thin film materials with catalytic properties.

Surface-Mounted Metal–Organic Frameworks: Past, Present, and Future Perspectives

“…Vohra et al encapsulated guest Pd[P-(C 6 H 5 ) 3 ] 4 catalysts (Pd−Cs) into porphyrin-based SURMOF PIZA-1 thin films. 75 The Pd−Cs@PIZA-1 SURMOF unites the oxidation activity of Pd−Cs and the acetalization activity of the Lewis acid sites in the PIZA-1 film, showing excellent catalytic activity in tandem oxidation−acetalization on benzyl alcohol and ethylene glycol. Moreover, by controlling the top layer terminated with different surface precursors [Co(OAC) 2 , the TCPP ligand, or Pd−Cs], the obtained Pd−Cs@PIZA-1 SURMOFs had different catalytic conversion ratios (85.0, 71.9, and 70.0%, respectively).…”

MOFs based on 1D structural sub-domains with Brønsted acid and redox active sites as effective bi-functional catalysts

“…34 Specifically, described catalysts used for carrying out alcohol oxidation and acetalization reactions were meanly Pd-mineral acids, magnesium oxide, Pd-metalloporphyrin or Pd-UiO66-NH2. [74][75][76][77] As valuable alternative, a specific bi-functional metal-organic catalyst combining Brønsted acid and redox active sites, Al-ITQ-SO3H/Pd was prepared. The studied two steps reaction consists in the first step in the oxidation of benzyl alcohol (1) into benzaldehyde (2) under O2 atmosphere catalysed by Pd nanoparticles, and in the second step in the acetalization of benzaldehyde with methanol to give the corresponding dimethylacetal (3) (Scheme 5).…”

Layer-by-layer spray preparation of SURMOF and their applications

“…图 4 HKUST-1吸附不同染料前后的紫外可见光谱: 吸附 MB (a); 吸附NFR (b); 吸附MB/NFR (1:1) (c) [44] (网络版彩图) 薄膜与粉末PIZA-1的质量吸收比较(g)和对苯、甲苯和对二甲苯的选择性比较(h) [46] (网络版彩图) 图 6 (a) 亚甲基蓝(MB)降解的时间依赖性C/C 0 ; (b) 4-硝基苯酚还原的随时间变化的ln(C/C 0 ) [14] (网络版彩图) 底物. 如此重复60个生长循环(图7(a)) [13] .…”