Highly active Pd containing EMT zeolite catalyst for indirect oxidative carbonylation of methanol to dimethyl carbonate

Abstract

An efficient catalytic system for the synthesis of glycerol carbonate by oxidative carbonylation of glycerol

Mechanical pressure-mediated Pd active sites formation in NaY zeolite catalysts for indirect oxidative carbonylation of methanol to dimethyl carbonate

“…The TEM images of fresh and used Pd/NaY-60 catalysts indicated that the large Pd nanoparticles were formed because of the catalytic test. This was in line with the previous observation revealing the palladium sintering on the Pd/NaY catalyst after the catalytic test [41]. The used Pd/NaY-150 catalyst contained Pd nanoparticles of 6.3 nm that were remarkably smaller than the counterparts on the Pd/NaY-60 catalyst (Fig.…”

“…As described previously, the Pd/NaY catalyst was prepared by an ion-exchange method with Pd precursor of Pd(NH 3 ) 4 2+ ; and the low-temperature calcination at 200 ºC caused the Pd(NH 3 ) 4 2+ to lose partially the NH 3 ligands and to generate the Pd(NH 3 ) n 2+ (n  2) sites on the catalyst [41]. Neither Pd clusters (below 2 nm) nor nanoparticles were observed on the fresh Pd/NaY-60 catalyst before the catalytic test (Fig.…”

“…Tan et al found that Pd/NaY catalyst with mononuclear-isolated Pd 2+ centers was stable for at least 100 h [35], but the selectivity of inevitable byproducts such as methyl formate and dimethoxymethane was not disclosed. Recently, we reported on the preparation of stable Pd/EMT catalyst tested for 130 h. We found that the EMT zeolite framework could inhibit the palladium sintering and maintain the Pd 2+ active sites [41]. The chlorine-free Pd-based catalysts are still under development, and the bottleneck for their industrialization is the lack of sufficiently active and stable catalysts.…”

Effect of Cobalt Doping on the Stability of CaO‐Based Catalysts for Dimethyl Carbonate Synthesis via the Transesterification of Propylene Carbonate with Methanol

“…In addition, DMC is also widely used as a fuel oil additive due to its high oxygen content (53 %) [4] and employed as a key solvent in the synthesis of commodity polymers [5] . There are several routes for producing DMC, such as the oxidative carbonylation of methanol, [6] direct synthesis from CO 2 and methanol, [7,8] methanolysis of urea, [9] and transesterification of cyclic carbonate (propylene carbonate or ethylene carbonate) with methanol [10,11] . Therefore, DMC synthesis via the transesterification of propylene carbonate (PC) with methanol under mild conditions is a clean catalytic route eliminating the use of toxic and corrosive reagents and is recognized as a promising and environmentally benign route for DMC.…”

Crystalline Microporous MoVBiO Polyoxometalates for Indirect Oxidation of Methanol to Methyl Formate: Effects of Organic Additives on Crystals Size and Catalytic Performance

“…The DRIFTS spectra of pyridine absorbed on samples MoVBiO‐M‐120, MoVBiO‐N‐120, MoVBiO‐T‐120 and MoVBiO‐T‐175 are presented in Figure 10. The weak band at 1446 cm −1 is assigned to the Lewis‐bound pyridine [58] . The band at 1537 cm −1 corresponds to Brønsted‐bound pyridine, and the band at 1487 cm −1 is assigned to pyridine associated with both Lewis and Brønsted acid sites [58] .…”