Insights into the Pyrolysis Processes of Ce-MOFs for Preparing Highly Active Catalysts of Toluene Combustion

Abstract

Metal organic frameworks (MOFs) have recently been used as precursors of the catalysts for the combustion of volatile organic compounds (VOCs). In the present work, three kinds of CeO 2 catalysts were successfully synthesized from Ce-MOF-808, Ce-BTC, and Ce-UiO-66, with specific topological structures and coordinate environments. Catalysts with small particle size, stacking mode, and structural defects could be created by pyrolysis of Ce-MOFs, which affects the activity in the toluene combustion significantly. Raman spectra, XPS, and OSC studies were performed to reveal the formation of defect sites. The thermal redox properties were determined by H 2 -TPR. Catalytic activity tests were conducted on the toluene combustion, and CeO 2 -MOF-808 showed the best catalytic performance (T90 = 278 • C) due to its having the largest specific surface area, abundant active surface oxygen species, and low-temperature reducibility.

Catalytic Combustion of Toluene over Highly Dispersed Cu-CeOx Derived from Cu-Ce-MOF by EDTA Grafting Method

“…The overall catalytic performance results showed that the samples with the most surface reactive oxygen species had the best catalytic activity. With the incorporation of Cu, the T 90 of Cu-CeO x -MOF-n declined obviously and the catalytic activity under high conversion enhanced significantly in comparison to CeO 2 -MOF-808, whose T 90 was tested 278 • C in our previous stage of work [22]. In addition, the Cu-CeO x -MOF-0.2 catalysts had decent catalytic expression under different WHSVs (Figure 7b).…”

“…In our previous work, Ce-MOF-808 with three-dimensional porous structure was used as the precursor to prepare the CeO 2 catalyst. The prepared CeO 2 -MOF-808 with large specific surface area and abundant active sites showed good catalytic performance [19,22]. The uniformity of metal-organic frameworks (MOFs) [23,24] provides the possibility for highly dispersed introduction of Cu [25].…”

Porous MOF-808@PVDF beads for removal of iodine from gas streams

“…In the stage between 100 C and 320 C, all the samples undergo slow decomposition of MOF-808, releasing coordinated water, DMF solvent molecules and formic acid ligands. 27 The weight losses at this stage are about 20%, 14%, 9% and 6% for MOF-808, 808-PVDF0.7, 808-PVDF0.5 and 808-PVDF0.3, respectively. Because there is almost no weight loss for pure PVDF polymers before 400 C, 28 we could calculate that the contents of MOF-808 in 808-PVDFx are about 70%, 45% and 30% for 808-PVDF0.7, 808-PVDF0.5 and 808-PVDF0.3, respectively.…”

Rare‐Earth‐Based Metal–Organic Frameworks as Multifunctional Platforms for Catalytic Conversion

“…The Ce-based MOFs were treated as precursors to obtain CeO 2 catalysts for effective degradation of 4-nitrophenol, toluene, o-xylene, and dyes (Figure 6). [107][108][109][110] The prepared CeO 2 -based catalysts from MOF materials can maintain the general morphology and realize the effective reduction/ oxidation of organic pollutions. The porous structure of MOFs can effectively enhance the catalytic activity of obtained CeO 2 catalysts, which can effectively degrade these organic pollutions.…”