RESUMEN
Catalytic decomposition of the hydrogen-rich hydrazine monohydrate (N2H4·H2O) represents a promising hydrogen storage/production technology. A rational design of advanced N2H4·H2O decomposition catalysts requires an overall consideration of intrinsic activity, number, and accessibility of active sites. We herein report the synthesis of a hierarchically nanostructured NiPt/N-doped carbon catalyst using a three-step method that can simultaneously address these issues. The chelation of metal precursors with polydopamine and thermolysis of the resulting complexes under reductive atmosphere resulted in a concurrent formation of N-doped carbon substrate and catalytically active NiPt alloy nanoparticles. Thanks to the usage of a silica nanosphere template and dopamine precursor, the N-doped carbon substrate possesses a hierarchical macroporous-mesoporous architecture. This, together with the uniform dispersion of tiny NiPt nanoparticles on the carbon substrate, offers opportunity for creating abundant and accessible active sites. Benefiting from these favorable attributes, the NiPt/N-doped carbon catalyst enables a complete and rapid hydrogen production from alkaline N2H4·H2O solution with a rate of 1602 h-1 at 50 °C, which outperforms most existing catalysts for N2H4·H2O decomposition.
RESUMEN
In order to ascertain the optimal hormone combination for Chinese fir (Cunninghamia lanceolata) leaf cuttings, an L16(4)4 orthogonal test of 6-benzylaminopurine (6-BA), 1-naphthaleneacetic acid (NAA), and indole-3-butyric acid (IBA) (0, 10, 30, or 50 mg · L-1 of each exogenous hormone) immersion for 5, 10, 15, or 20 min was conducted. Callus initiation rate and rooting promotion rate were mainly affected by treatment time, root length increase by 6-BA concentration, and bud germination rate and plantlet formation rate by NAA concentration. The expected optimal combination for callus initiation rate was 50 mg · L-1 6-BA + 0 mg · L-1 NAA + 30 mg · L-1 IBA + 10 min; for rooting promotion rate, it was 0-10 mg · L-1 6-BA + 10 mg · L-1 NAA + 30 mg · L-1 IBA + 20 min; for bud germination rate, it was 50 mg · L-1 6-BA + 0-10 mg · L-1 NAA + 0-30 mg · L-1 IBA + 20 min; and for seedling formation rate for No. 4, it was 10 mg · L-1 6-BA + 10 mg · L-1 NAA + 0 mg · L-1 IBA + 20 min. Light microscopy image analysis revealed that a cluster of primordial cells was produced 40 days after cutting, and mastoid cells developed into peninsula cells in calli that were cultured for 50 days.