XPS, XAES, and TG/DTA characterization of deposited carbon in methane dehydroaromatization over Ga–Mo/ZSM-5 catalyst

Recent progress in methane dehydroaromatization: From laboratory curiosities to promising technology

“…Figure 3 shows the range of second metal additives tested, including Fe [176−178], Co [176, 179−181], Ni [182,183], Cu [19,20,135], Zn [184,185], Ga [112,178,186], Cr [187], Ag [183,188], In [189], Pd [190], Ir [190], Zr [191], A l [178], W [191,192], P [71,178,193], Li [71], V [191], B [188], Pt [194], Ru [194], Mg [195], Ce [14], La [14], and Re [14]. Of all the metal additives, Fe, Co, Ni, Cu, Zn, Ga, Cr, Ag, and In showed the best performance: each was reported to improve the catalytic activity, benzene selectivity, and catalyst stability.…”

“…2 nm, and on the zeolite surface in the form of a friable disordered layer with a thickness up to 3 nm. Liu et al [112] characterized the nature of deposited carbon by means of XPS, XAES, TG/DTG, HRTEM, and DTA techniques. Their results confirmed that sp 2 /sp 3 ratio of the coke increases with time-on-stream, sug-gesting that the deposition of polyaromatic-type carbon is the main reason for catalyst deactivation.…”

Microstructured Al‐fiber@meso‐Al2O3@Fe‐Mn‐K Fischer–Tropsch catalyst for lower olefins

“…48 Other peaks at 286.5, 288.9, and 293.0 eV are attributed to alkene species, carbonyl species, and aromatic-type carbon species, respectively. 50 Figure 8B presents Raman bands of the used catalysts, and the G (graphite) band at 1600 cm 21 as well as D (distorted) band at 1328 cm 21 indicates the graphite-like carbon deposits. 48 These results indicate the coexistence of amorphous carbon and graphitic carbon on the working catalysts, which is consistent with previous reports.…”

Performance of 3%Mo/ZSM-5 catalyst in the presence of water during methane aromatization in supersonic jet expansion

“…8 The HZSM-5 zeolite with SiO 2 /Al 2 O 3 ratio of 25 was supplied by Nankai University (China). The zeolite was stirred in a solution of ammonium heptamolybdate at room temperature (RT) for 24 h, and then dried at 120 C for 3 h, and calcined in air at 500 C for 4 h. A VGX 900 spectrometer with multichannel detector and Mg K a radiation (1253.6 eV) was used for XPS investigation.…”

“…We characterized the nature of carbon deposition on Ga-Mo/ZSM-5 and made suggestion on the cause of catalyst deactivation. 8 We reported that…”