Interactions between atomically dispersed copper and phosphorous species are key for the hydrochlorination of acetylene

Vinyl chloride, the monomer of polyvinyl chloride (PVC), is industrially synthesized via acetylene hydrochlorination. Thereby, easy to sublimate but toxic mercury chloride catalysts are widely used. It is imperative to find environmentally friendly non-mercury catalysts to promote the green production of PVC. Low-cost copper-based catalysts are promising candidates. In this study, phosphorus-doped Cu-based catalysts are prepared. It is shown that the type of phosphorus configuration and the distribution on the surface of the carrier can be adjusted by changing the calcination temperature. Among the different phosphorus species, the formed P-C bond plays a key role. The coordination structure formed by the interaction between P-C bonds and atomically dispersed Cu2+ species results in effective and stable active sites. Insights on how P-C bonds activate the substrate may provide ideas for the design and optimization of phosphorus-doped catalysts for acetylene hydrochlorination.

Voltammetric Amitriptyline Determination Using a Metal-Free Electrode Based on Phosphorus-Doped Multi-Walled Carbon Nanotubes

A new electrode material of phosphorus-doped multi-walled carbon nanotubes (P-MWCNTs) was developed as an electrochemical sensing element for amitriptyline (AMT). P-MWCNTs were hydrothermally synthesized and drop casted on a glassy carbon electrode (P-MWCNTs/GCE). The P-MWCNTs were morphologically, chemically and structurally characterized. The electrochemical characteristics of the P-MWCNTs/GCE were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and adsorptive stripping voltammetry (AdSV). The P-MWCNTs increased electron transfer at the GCE and the electrochemical conductivity of the electrode. Electrocatalytic activity toward the oxidation of AMT was excellent. In the optimal voltammetric condition, the P-MWCNTs/GCE produced linear ranges of 0.50 to 10 µg mL-1 and 10 to 40 µg mL-1. The limit of detection (LOD) and limit of quantification (LOQ) were 0.15 µg mL-1 (0.54 µM) and 0.52 µg mL-1 (1.80 µM), respectively. The developed sensor displayed good repeatability, reproducibility and specificity. The sensor successfully quantified AMT in pharmaceutical tablets, giving results consistent with spectrophotometric analysis. The sensor achieved recoveries from 98±2% to 101±5% from spiked urine samples. The proposed sensor could be applied to determine AMT in pharmaceutical and urine samples for forensic toxicology.