Thermal decomposition kinetics of M−BTC (M = Cu, Co, Zn, and Ce) and M−BTC/Pt composites under oxidative and reductive environments

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-12, Vol.450, p.138470, Article 138470
• Main Authors: Chen, Bin, Zeng, Xiaoli, Liu, Yiping, Xiao, Fulan, Huang, Mingzhen, Bing Tan, Kok, Cai, Dongren, Huang, Jiale, Zhan, Guowu
• Format: Article
• Language: English
• Subjects: Decomposition kinetic; In-situ DRIFTS; Metal-organic framework; Thermostability
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.138470

[Display omitted] •Pt NPs promoted the thermal decomposition process of MOFs in air atmosphere.•Pt NPs facilitated the formation of UMCs by the removal of coordinated solvent.•The Ea change in air was determined by both LMCT effect and O2 adsorption capacity.•Overflow effect of atomic H accelerated the decomposition rate of MOFs.•Ligand hydrogenation led to the enhanced thermostability of MOFs with higher Ea. Metal-organic frameworks (MOFs) have been utilized as an important precursor/template to prepare diverse metal or metal oxide nanomaterials. Herein, we studied the thermal decomposition behaviors of M−BTC (M = Cu, Co, Zn, and Ce; BTC = benzene-1, 3, 5-tricarboxylate) and the Pt-supported M−BTC nanocomposites (M−BTC/Pt) in different atmospheres by using thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), in-situ X-ray diffractometer (in-situ XRD), and in-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS). The results indicated that the presence of Pt promoted the decomposition of the Cu-BTC, Co-BTC, and Zn-BTC under air atmosphere with lower activation energies. For instance, the Ea values of the decomposition process of Cu-BTC and Cu-BTC/Pt were 231 and 133 kJ/mol, respectively, which can be attributed to the enhanced ligand-to-metal charge transfer effect and higher oxygen adsorption capacity after the immobilization of Pt. However, the thermal decomposition of Ce-BTC showed a different trend with a larger Ea value in the presence of Pt (167 vs 105 kJ/mol). In-situ DRIFTS showed that the introduction of Pt would change the thermal decomposition modes of MOFs by the strong hydrogen overflow effect. However, the improved thermostability of Cu-BTC, Co-BTC, and Zn-BTC in the hydrogen atmosphere is owing to the hydrogenation of the carboxylate on the organic linkers. For instance, the Ea values of the decomposition process of Co-BTC and Co-BTC/Pt were 197 and 237 kJ/mol, respectively. Such findings could provide reference and guidance for further understanding of the effects of metal nanoparticles on the thermal decomposition of MOFs for controlling the physicochemical properties of the MOF-derived metal oxide nanomaterials.