One-pot synthesis of Pt–Sn bimetallic mesoporous alumina catalysts with worm-like pore structure for n-butane dehydrogenation

Antibacterial composite: polymeric mesoporous silica nanoparticles and combination of imipenem/meropenem

Using nanomaterials is a novel strategy to eliminate drug resistance against bacteria. Nanoparticles with metal sites show antimicrobial activities that counteract or obstruct antibiotic-resistant mechanisms expressed by the pathogens. Here, a nanocomposite based on mesoporous silica nanoparticles with active sites of silver, and a combination of imipenem and meropenem as antibiotic drugs, was synthesized and characterized using different physicochemical methods. The antibacterial assessments exhibited sensitivity by Staphylococcus aureus (S. aureus), Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli) toward the synthesized composite, which showed a suitable safety profile in human cells. This composite has an excellent synergic mechanism based on reactive oxygen species (ROS) to kill bacteria due to penetrating the microbial membrane. In addition, this composite is resistant to hydrolysis by plasmids and chromosomally mediated β-lactamases. This nanocomposite showed extraordinary antiseptic power against Gram-positive and Gram-negative microbes.

One-Step Fabrication of PtSn/γ-Al2O3 Catalysts with La Post-Modification for Propane Dehydrogenation

The catalytic dehydrogenation of propane to propene is an alternative technique to supplement the traditional steam cracking and catalytic cracking process for satisfying the continuously increasing demand for propylene downstream products. In this study, the parent PtSn/γ-Al2O3 catalyst was fabricated via the one-step method for the subsequent La post-modification to prepare the catalysts for propane dehydrogenation. The prepared and spent catalysts were characterized by X-ray diffraction (XRD), N2 adsorption–desorption, scanning electron microscope (SEM), NH3 temperature-programmed desorption (NH3-TPD), H2 temperature-programmed desorption (H2-TPR), and thermogravimetric (TG) analysis. The catalytic performance and characterization results demonstrated that the addition of La into the parent catalyst could significantly improve the catalytic performance of the prepared catalyst. Especially, the PtSn-La2.2 catalyst with the 2.2 wt.% La addition exhibited the stable and highest propylene selectivity (>84%) under the investigation time of 800 min. The introduced La exhibits the ability to adjust the textural properties of the obtained catalysts, curb the acidity of support, promote the reduction of Pt species, and reduce the carbon accumulation on the prepared catalysts.