Elucidation of the reaction mechanism of indirect oxidative carbonylation of methanol to dimethyl carbonate on Pd/NaY catalyst: Direct identification of reaction intermediates

Tunable Transesterification of Dimethyl Carbonate with Ethanol on K2CO3/Al2O3 Catalysts: Kinetic Modeling

“…46 The bands of the methoxy species at 2936, 2808, 1398, 1299, and 1060 cm −1 were also observed, which indicate the dissociative adsorption of DMC on K 2 CO 3 /γ-Al 2 O 3 . 43,47,48 However, an obvious negative band at 1653 cm −1 was observed in the IR spectra of DMC adsorbed on γ-Al 2 O 3 , which could be attributed to the desorption of dissociative adsorbed DMC. 48 This phenomenon suggested that γ-Al 2 O 3 displayed a weaker adsorption capacity for DMC compared with K 2 CO 3 .…”

“…However, the C–H vibration of the methoxy species between 2800 and 3000 cm –1 was not observed for DEC adsorbed on K 2 CO 3 /γ-Al 2 O 3 and γ-Al 2 O 3 . Instead, two obvious negative bands at 1749 and 1283 cm –1 were formed in the spectra of DEC adsorbed on K 2 CO 3 /γ-Al 2 O 3 , which could be attributed to the desorption of the dissociated adsorbed DEC and the perturbation of the inorganic carbonate group on the catalyst surface. , Therefore, it suggested that DEC showed a weak adsorption on the catalyst surface.…”

“…Instead, two obvious negative bands at 1749 and 1283 cm −1 were formed in the spectra of DEC adsorbed on K 2 CO 3 /γ-Al 2 O 3 , which could be attributed to the desorption of the dissociated adsorbed DEC and the perturbation of the inorganic carbonate group on the catalyst surface. 46,47 Therefore, it suggested that DEC showed a weak adsorption on the catalyst surface. The relative weak adsorption of carbonates could efficiently promote the transesterification reactions and the desorption of carbonate products.…”

Theoretical exploration of the origin of selectivity for the oxidative carbonylation reaction catalyzed by a single Pd atom embedded on graphene

“…Over the past decades, many Pd-based catalysts employing various catalytic supports have been reported to be effective for the reaction, including carbon materials, [5][6][7] metal oxides, [8][9][10][11] and porous materials. [12][13][14][15][16][17][18][19] For the rational development of related catalysts, it is necessary to gain molecular insight into the reaction mechanisms and to understand the relationship between the selectivity and the structures of catalysts.…”

“…Indeed, the adsorbates involved in the reactions, including the adsorbed substrates and intermediates, have been understood by employing both theoretical and in situ experimental methods in previous studies. [19][20][21][22][23][24][25][26][27] The *COOCH 3 intermediate is observed in the generation of both DMC/DMO by using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). *COOCH 3 is formed by the oxidative carbonylation of *OCH 3 and *CO (* means a surface site and is the same in this context).…”