Enhancement of the catalytic performance in Pd-Cu/NaY catalyst for carbonylation of methyl nitrite to dimethyl carbonate: Effects of copper doping

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

“…The Pd(NH 3 ) 4 Cl 2 solution was added dropwise into the activated NaY zeolite slurry containing 1.0 g zeolite and 100.0 g deionized water. The resulting suspension was stirred at room temperature (25 ºC) for 12 h and subsequently was heated at 80 ºC to evaporate the excess ammonia until the pH value of the suspension decreased to 7.07.2 [35,36]. Then the solid was collected by vacuum filtration and washed thoroughly with deionized water.…”

“…Various chlorine-free Pd catalysts have been investigated, and the most appropriate catalyst support was NaY zeolite in comparison to NaX, -Al 2 O 3 , -Al 2 O 3 , silica, and MgO [31,34,35]. Guo et al revealed that the copper promoter could improve the Pd dispersion and maintain the Pd 2+ active sites on the Pd/NaY catalyst [36]. Dong et al reported that potassium-doped Pd/NaY catalyst enhanced the activation of CO reactant by forming a Pd-COK + structure [37].…”

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

“…Dong et al demonstrated that the potassium promoter improved the electron density of Pd clusters and thus enhanced the activation of CO reactant on the Pd/FAU catalyst; both theoretical and experimental proofs were provided [12]. Guo et al reported that the Cu-doped Pd/ FAU catalyst showed higher activity and selectivity than the Cu-free Pd/FAU catalyst, possibly due to the increased Pd 2+ /Pd 0 ratio of Pd clusters [17]. It is accepted that Brønsted acidity can accelerate the decomposition of CH 3 ONO reactant, and result in poor catalyst selectivity [1].…”

Synthesis of High-Performance and High-Stability Pd(II)/NaY Catalyst for CO Direct Selective Conversion to Dimethyl Carbonate by Rational Design

“…Using Pd­(II)-based catalysts in the first reaction led to the production of DMC (Scheme ). However, the reduction of Pd­(II) to Pd(0) is inevitable in the presence of CO, which leads to the production of dimethyl oxalate (DMO). − Industrial application of this CO direct catalytic conversion route is therefore impeded by the stability of the catalyst used. Furthermore, the molecular mechanism behind this selectivity remains uncertain, making it more difficult to improve the catalyst used herein.…”