Hollow Carbon Nanospheres Decorated with Abundant Pyridinic N⁺O^– for Efficient Acetylene Hydrochlorination

Abstract

Considering the disadvantages of metallic catalyst and benchmark commercial activated carbon for acetylene hydrochlorination, such as considerable cost, metal loss, serious carbon deposition, and insufficient active sites, nonmetal hollow carbon nanospherical materials (PACP-T) with hierarchical porous structures were synthesized by the copolymerization of aniline and pyrrole via a self-templating method. Local active sites were constructed by decorating the carbon material with heteroatomic groups. The synthetic process dispersed active sites at the atomic level, which was promoted by local structural forces. Experiments and DFT calculations showed that most active sites were pyridinic N+O–. The superior activity might have been caused by the synergistic adsorption and activation of reactants by highly electronegative heteroatoms and abundant π-containing functional groups (CC, NCN, aromatic ring, and pyridinic N+O–) at active sites on the catalyst. This promoted rapid reactions and impeded carbon deposition, which promoted the continuous exposure of active sites. The significantly improved activity and stability of the optimized PACP-800 catalyst promote its potential industrial applications.

Construction of Highly Dispersed Cu–P/Cl Active Sites Using Methyldiphenyloxophosphine for Efficient Acetylene Hydrochlorination

“…The ability of the catalytic active sites to adsorb and activate the gaseous is key to the catalytic reaction. Highly electronegative O atoms from carbonyl and other O-containing groups on the support surface attacked the H atoms in the HCl molecules, activating the H–Cl bond and leading to an HCl desorption peak at about 270 °C for AC (Figure a) . Further, the introduction of the Cu precursor resulted in a strong desorption at 337 °C for Cu/AC, which is mainly related to the adsorption and activation of HCl by the electron cloud around the Cu active center.…”

“…Highly electronegative O atoms from carbonyl and other O-containing groups on the support surface attacked the H atoms in the HCl molecules, activating the H−Cl bond and leading to an HCl desorption peak at about 270 °C for AC (Figure 10a). 60 Further, the introduction of the Cu precursor resulted in a strong desorption at 337 °C for Cu/AC, which is mainly related to the adsorption and activation of HCl by the electron cloud around the Cu active center. Notably, the introduction of the MDPO ligand having a highly reactive benzene ringcontaining P�O structure that can form hydrogen bonds with HCl triggered the multistate adsorption of the 15% Cu 8 MDPO 1 /AC catalyst with an enhanced adsorption capacity.…”

Construction of Ru–N Single Sites for Effective Acetylene Hydrochlorination: Effect of Polyethyleneimine Modifiers

“…Moreover, by comparing the ΔS BET % values of catalysts in the order of Ru/AC (58.8%) > Ru/AC@PEI-900 (45.0%) > Ru/AC@PEI-300 (37.0%) > Ru/AC@PEI-700 (30.8%) > Ru/AC@PEI (15.0%), the decreased S BET and V P may be due to the pore coverage caused by collapse or coking deposition resulting from the polymerization of VCM or C 2 H 2 during the test. 48 TGA was conducted to assess the carbon deposition resistance of the Ru catalysts. As for the Ru/AC@PEI samples (Figure 7), according to the analysis method in the literature, 10 the weight loss of the sample can be divided into three stages: <150, 150−389, and >389 °C, corresponding to the weight loss caused by the desorption of moisture on the samples' surface, the combustion of carbon deposition, and the combustion of carbon matrix, respectively.…”

“…This effect may be due to the high-temperature carbonization of polyethyleneimine on the catalyst’ surface, forming more Ru–N–C interfaces and producing a new fluffy structure. Moreover, by comparing the Δ S BET % values of catalysts in the order of Ru/AC (58.8%) > Ru/AC@PEI-900 (45.0%) > Ru/AC@PEI-300 (37.0%) > Ru/AC@PEI-700 (30.8%) > Ru/AC@PEI (15.0%), the decreased S BET and V P may be due to the pore coverage caused by collapse or coking deposition resulting from the polymerization of VCM or C 2 H 2 during the test …”

Phthalimide Ligand Coordination as a Critical “Key” for Constructing Chlorine–Platinum–Nitrogen Single-Site Catalysts for Effective Acetylene Hydrochlorination

“…The density functional theory (DFT) calculations were calculated on the Gaussian 16 program . B3LYP was employed for geometry optimization.…”