V. G. Slutskii

Interaction of ammonia with organoboron nanoparticle-based coatings

The interaction between ammonia and (C2B10H4)n nanoparticle-coated and uncoated graphite plates combined with molybdenum surface heated to 700 K was investigated. It was found that in both cases the interaction leads to the decomposition of ammonia into hydrogen and nitrogen; however, the presence of organoboron nanoparticles (OBN) accelerates this process. The tunneling current-voltage dependences of the nanoparticles before and after interaction with NH3 were measured. The close similarity of the measured I–V curves suggests that the interaction preserves the organoboron-nanoparticle electronic structure.

Effect of the substrate material on the catalytic decomposition of ammonia on organoboron nanoparticles

The catalytic decomposition of ammonia on (C2B10H4)n organoboron nanoparticles deposited onto SiO2, Al2O3, and graphite substrates at 750 K and 10–6 Torr is studied. The effect of the substrate material on the rate of NH3 decomposition is established. It is demonstrated that the replacement of SiO2 by Al2O3 or graphite increases the decomposition rate 1.9- and 2.3-fold, respectively. The catalytic activity of the nanoparticles increases with the contact potential difference between the nanoparticles and the substrate. The potential difference between the nanoparticles particles and the SiO2, Al2O3 and graphite substrates are found to be–0.5,–0.2, and 0.0 V, respectively.

Organoboron nanoparticles: synthesis, structures, and some physicochemical properties

Organoboron nanoparticles synthesized from carborane C2B10H12 by high-temperature pyrolysis of carborane vapor were investigated. The structures, electronic characteristics, and related physicochemical properties were found to depend on the sizes and shapes. The data of quantum chemical calculations performed in the framework of the density functional theory also indicate a relationship between sizes, dimensionalities, and electronic structure of the nanoparticles.

Autoignition of ethylene in shock waves

The delay time of ignition of various C2H4-O2-Ar mixtures behind reflected shock waves were measured at temperatures of 1090–1520 K and a pressure of 0.65 ± 0.05 MPa. A kinetic scheme of the ignition of ethylene based on the known rate constants of the key elementary reactions was developed. The scheme satisfactorily describes our own and published data on the ignition of ethylene in shock waves over wide ranges of temperature (1100–2400 K), pressure (0.006–0.64 MPa) and ethylene (0.1–17.4 vol %) and oxygen (0.6–20.7 vol %) concentrations.

The synthesis of boron-containing nanoparticles inert at room temperature

Boron-containing (C2B4H2)n nanoparticles with size 6.7, 7.8, and 10.8 nm inert at room temperature were synthesized. The synthesis was performed by the pyrolysis of gaseous carborane C2B4H6 at 1200–1280 K and the initial carborane pressure (5–25) × 10−3 MPa. An analytic dependence relating the size of nanoparticles to the temperature and initial carborane pressure was obtained.

Correlation between the catalytic activity of polyoxometallates and the special features of their tunnel and optical spectra

The tunnel spectra of phosphomolybdic acid, a classic heteropoly acid with a Keggin anion, were measured in ultrahigh-vacuum experiments with the use of scanning tunnel microscopy. The dependences of the resonance characteristics of the spectra, “negative differential resistances,” on the vacuum gap, material of contacts, and field polarity were studied. An earlier unknown mechanism of the formation of these characteristics was described. The mechanism included the action of strong electric fields in scanning tunnel microscope nanocontacts and a low degree of the delocalization of Keggin anion peripheral electrons. Strong electric fields (∼107 V/cm) characteristic of spectroscopic measurements with the use of scanning tunnel microscopes could break exchange bonds in heteropoly acids and their derivatives. This produced spectroscopic effects of interest for catalysis and nanoelectronics.

Ignition of acetylene-oxygen mixtures behind shock waves

The delay time of ignition of C2H2-O2-Ar mixtures of various compositions behind reflected shock waves were measured at 980–1300 K and 0.65 ± 0.05 MPa. A kinetic scheme of the ignition of acetylene based on the available rate constants of the key elementary reactions was developed. The scheme satisfactorily describes the experimental data from various works over wide temperature, pressure, and concentration ranges: 980–2400 K, 0.01–1.0 MPa, and 0.5–20.3 vol % acetylene and 1.25–20.4 vol% O2.

Ammonia decomposition on a platinum nanocoating at various electric potentials

It was shown that the rate of ammonia decomposition on a platinum nanocoating can be controlled by applying an external electrostatic field to the coating to create a negative or positive platinum potential of variable magnitude. In experiments conducted with a contact time of 15 min between platinum and ammonia at a temperature of 700 K and a pressure of 5 × 10–7 Torr, the decomposition rate increased by 44% at a negative potential of the coating of–6 V and by 70% at a positive potential of +6 V.

Effect of the electric potential of organoboron nanoparticles on their catalytic activity in the decomposition of ammonia

For the first time, it has been shown that the rate of the catalytic decomposition of ammonia over (C2B10H4)n organoboron nanoparticles can be controlled via generating an electric potential of different polarity and magnitude on the particles using an external voltage source. At a temperature of 700 K, a pressure of 10–6 Torr, and a positive potential of the particles of +6 V, the decomposition rate increases by 26%, while at a negative potential of–6 V, it decreases by 37% compared to the decomposition rate of ammonia at a zero potential of the particles.

Catalytic hydrogenation of ethylene on organoboron nanoparticles formed by pyrolysis of C2B10H12 carborane

The ability of organoboron nanoparticles (C2B10H4)n to multiply enhance the yield of C2H6 in the hydrogenation of C2H4 at temperatures 770–970 K is experimentally demonstrated. The observed acceleration is of catalytic nature, since the electronic structure of the nanoparticles remains unchanged in the hydrogenation reaction.