We present a comprehensive
mechanistic study on the highly tunable
selectivity over In
x
/ZrO2 catalysts
in CO2 hydrogenation. By variation of the indium loading
between 0.1 and 5 wt %, either an admirable selectivity to methanol
of 70–80% or up to 80% selectivity to CO could be obtained
in the temperature range of 250–280 °C. It is shown that
the shift in the product spectrum is related to the synergy between
indium species and the zirconia substrate through variable interfacial
structures. Zirconia-modulated crystalline In2O3, which prevails for indium loadings between 2.5 and 5 wt %, could
enhance stepwise hydrogenation of *HCOO, leading to *H3CO and finally methanol due to the suitable bonding strengths of
*HCOO and *H3CO. Regarding CO, evidence has been provided
that the synergistic effect between adjacent indium and zirconia sites
is indispensable for the entire catalytic cycle. *HCOO is formed at
the indium–zirconia interfaces and decomposes to CO subsequently.
Highly dispersed InO
x
dominating for loadings
below 0.5 wt % features an enormous indium–zirconia interface
and suppresses hydrogenation ability for *HCOO, thus favoring the
generation of CO. The study provides fundamental insights into the
mechanism of CO2 conversion and reaction pathway tuning
over oxide catalytic systems.
Implant-associated bacterial infections pose serious medical and financial issues due to the colonization and proliferation of pathogens on the surface of the implant. The as-prepared traditional antibacterial surfaces can neither resist bacterial adhesion nor inhibit the development of biofilm over the long term. Herein, novel (montmorillonite/poly-l-lysine-gentamicin sulfate) ((MMT/PLL-GS)) organic-inorganic hybrid multilayer films were developed to combine enzymatic degradation PLL for on-demand self-defense antibiotics release. Small molecule GS was loaded into the multilayer films during self-assembly and the multilayer films showed pH-dependent and linear growth behavior. The chymotrypsin- (CMS) and bacterial infections-responsive film degradation led to the peeling of the films and GS release. Enzyme-responsive GS release exhibited CMS concentration dependence as measured by the size of the inhibition zone and SEM images. Notably, the obtained antibacterial films showed highly efficient bactericidal activity which killed more than 99.9% of S. aureus in 12 h. Even after 3 d of incubation in S. aureus, E. coli or S. epidermidis solutions, the multilayer films exhibited inhibition zones of more than 1.5 mm in size. Both in vitro and in vivo antibacterial tests indicated good cell compatibility, and anti-inflammatory, and long-term bacterial anti-adhesion and biofilm inhibition properties.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.