Ambient Temperature NO Adsorber Derived from Pyrolysis of Co-MOF(ZIF-67)

Abstract

Co-, Ni-, and Zn-containing MOFs are prepared and then pyrolyzed to generate materials for ambient temperature NO adsorption. Materials containing Co are much more efficient for NO adsorption than those containing Ni and Zn; therefore, Co is identified as the active phase. The best performing material studied here achieves 100% low concentration (10 ppm) NO adsorption for more than 15 h under a weight hourly space velocity of 120 000 mL g –1 h –1 . Powder X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared, and Raman spectroscopies, along with scanning electron microscopy and TEM, are used to probe the physicochemical properties of the materials, particularly the Co active phase, and chemistries involved in NO adsorption–desorption. NO adsorbs on oxygen-covered Co nanoparticle surfaces in the form of nitrates and desorbs as NO at higher temperatures as a result of surface nitrate decomposition. NO storage capacity decreases gradually upon repeated NO adsorption–desorption cycles, likely because of Co 3 O 4 formation during these processes.

Highly Dispersed Co/Zn-Doped Zeolitic Imidazolate Framework-Derived Carbon Nanoparticles with High NO Adsorption Capacity at Low Operating Temperature

“…Sun et al evaluated several porous materials, including MOFs and ZIFs, for the removal of SO 2 and NOx from flue gases using molecular simulations . They concluded that ZIF-8 exhibited moderate NOx adsorption performance at 100 kPa and 313 K. However, the experimental results of Lin et al revealed that the adsorption capacity of MOFs for trace NO in exhaust was negligible …”

Hydrogenation of furfural over Pd@ZIF-67 derived catalysts: direct hydrogenation and transfer hydrogenation

“…3c shows characteristic peaks of Co 0 (778.4 eV), Co 3+ (779.8 and 794.2 eV), and Co 2+ (781.4 and 798.1 eV), and along with satellite peaks (786.5 and 803.2 eV). 40 Most of the Co is present in oxidized states, largely as a result of the oxidization of the Co nanoparticles in air. 41 The XPS of C 1s (Fig.…”

A deactivation mechanism study of phosphorus-poisoned diesel oxidation catalysts: model and supplier catalysts

“…12 The low-temp peak (∼120°C) can be assigned to the weakly adsorbed NO and the other to more stable NO-adsorbed species due to the formation of nitrites and nitrates species. 46,47 Only small desorption features of NO x were detected for the poisoned catalysts, in the low temperature region. The total amounts of NO x desorption (equal to storage) were calculated and are displayed in Fig.…”