To
overcome the disadvantages of Cu-based catalysts, such as the
low dispersion of active components and insufficient active species,
several 15% Cu-L
x
/AC catalysts for acetylene
hydrochlorination were synthesized based on strong interactions between
a ligand and CuCl2 precursors. The introduction of the
methyldiphenyloxophosphine (MDPO) ligand effectively modulated the
electronic properties of the metal centers, which contributed to the
construction of a highly dispersed Cu–P/Cl local structure
with Cu1+/Cu2+ as a plausible active center.
The sintering of active components in the catalyst may be one of the
main reasons for the decrease in catalytic performance. Meanwhile,
the enhanced adsorption and activation of the catalyst for C2H2 and HCl molecules resulted in improved coking resistance.
The most active catalyst (15% Cu8MDPO1/AC) could
achieve a stable acetylene conversion of 97% at 180 °C, a gas
hourly space velocity (GHSV) (C2H2) of 180 h–1, and a feed volume ratio (V
HCl/V
C2H2
) of 1.15, outperforming the benchmark catalyst. The excellent activity
and stability in a 300 h laboratory test at a high GHSV and a 3414
h industrial sideline test at an industrial GHSV render the 15% Cu8MDPO1/AC catalyst as a reference for the construction
of other catalysts from an environmental, economic, and application
prospect perspective.
Owing to the low dispersion and deficiency of active
species in
Pt catalysts, Pt-complexes catalysts (Pt–L
x
/SAC–IPA) were synthesized using 2-propanol (IPA) solvent
via ligand coordination strategy. The IPA, which exhibits a low boiling
point and weak polarity, promotes the dispersion of Pt species. Further,
the introduction of phthalimide ligand (L1) modulates the
electronic properties of active metals, thereby constructing the single-site-dispersed
Cl–Pt–N local structure bearing Pt(II) (presumably the
active center of the reaction). Concurrently, the enhanced adsorption
and activation performances of the catalyst toward an HCl reactant,
as well as its weakened performances toward a C2H2 reactant, improve its anticoking performance and lower the reaction
energy barrier. Therefore, the most active Pt–L1/SAC–IPA catalyst achieves an outstanding performance comparable
with that of the standard Au/activated carbon (AC)–aqua regia
(AR) catalyst, and it is reasonable to conclude that the L1 ligand functioned as a critical “key” in the Pt-based
catalytic acetylene hydrochlorination.
The development of non‐noble metal catalysts is crucial for hydrogen production. In this study, electrochemically reconfigurable Fe2O3@NiO‐x composite catalysts were synthesized within tens of seconds using a simple microwave deposition method. Interestingly, Fe2O3@NiO‐5 exhibited a high‐speed and deep surface reconstruction capability, greatly enhancing the hydrogen evolution reaction (HER) activity. DFT calculations also confirmed that the reconstruction process optimized the adsorption energy of H2O and H intermediate to promote HER kinetics. The optimized Fe2O3@NiO‐5 electrode only afforded an overpotential of 295 mV at 10 mA cm−2 and it steadily functioned for 25 h for HER in 1 M KOH. In addition, benefiting from the combination of Fe2O3 and NiO layer during the synthesis process, Fe2O3 and NiO converted into FeOOH and NiOOH, respectively, resulted in the excellent oxygen evolution reaction (OER) activity of Fe2O3@NiO‐5. The as‐prepared Fe2O3@NiO‐5 only required an overpotential of 186 mV at 10 mA cm−2 and exhibited excellent stability for up to 144 h. As a bifunctional catalyst, the Fe2O3@NiO‐5 electrode can deliver a current density of 20 mA cm−2 at a low voltage of 1.78 V with high durability for water splitting. This work can provide a new perspective for constructing advanced non‐noble metal electrode.
Recently, the full-area defect inspection of high-performance optical components such as large telescope mirrors is urgently demanded. An industrial robotic arm is suitable for conducting the scanning movement of defect inspection systems, and another monitoring system is needed to guide the moving trajectory of the robotic arm. An efficient and precise guiding system is developed based on a laser projection measuring system. After the calibration of the measuring system, real-time point clouds of the component under test can be acquired. Denoising and registration of the point clouds are conducted to align the robot coordinate system with the workpiece coordinate system. Then, the scanning inspection can be conducted all over the component under test. Experimental results demonstrate that the system has high efficiency and accuracy within 17.59 μm
Defect site and nitrogen species in carbon materials directly affect its catalytic activity for acetylene hydrochlorination. However, there is often a negative correlation between the increase of defect sites and...
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