Partial oxidation of CH to synthesis gas using Ni-catalyst/Au|YSZ|Ag electrochemical membrane reactor

Takehira, Katsuomi; Shimomura, Junpei; Hamakawa, Satoshi; Shishido, Tetsuya; Kawabata, Tomonori; Takaki, Ken

doi:10.1016/j.apcatb.2004.08.002

Cited by 6 publications

(4 citation statements)

References 23 publications

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“…The catalyst synthesis carried out in this study was carried out electrochemically. Electrosynthesis with bipolar membranes has been successfully developed 17,18,19) . The production of Ni-B in hydroxyapatite (Ni-B/HA) and Cu-B in hydroxyapatite (Cu-B/HA) catalysts has also been carried out 20,21) .…”

Section: Introductionmentioning

confidence: 99%

The Release of Hydrogen from NaBH_4 with Ni-Cu-B/Hydroxyapatite as The Catalyst

Nur¹,

Jumari²,

Dyartanti³

et al. 2022

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The environmentally friendly combustion of hydrogen makes hydrogen an ideal fuel. Research on the ideal hydrogen storage is still being carried out. one candidate for hydrogen storage is NaBH4. NaBH4 is hydrolyzed to release hydrogen. This work concerns the hydrolysis reaction of NaBH4 to release hydrogen with a catalyst Ni-Cu-B deposited on hydroxyapatite. The research went through 2 stages, namely catalyst synthesis and NaBH4 hydrolysis reaction. The catalyst synthesis was carried out electrochemically using a 2-compartment electrochemical cell at the certain current density and reaction time. The hydrolysis reaction was observed in a batch reactor at a constant temperature. The results showed that the most significant hydrogen release at room temperature occurred with a catalyst made at 160 mA/cm 2 for 90 minutes. The hydrogen release rate ranged from 435 to 1600 mL H2/g catalyst/min. The resulting equation for the reaction rate constant as a function of temperature is k = 3.567 x 10 10 exp(8624.245/T).

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Section: Introductionmentioning

confidence: 99%

The Release of Hydrogen from NaBH_4 with Ni-Cu-B/Hydroxyapatite as The Catalyst

Nur¹,

Jumari²,

Dyartanti³

et al. 2022

Evergreen

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“…YSZ is a well-known ionic conductor due to doping of Y 3+ in the Zr 4+ lattice, generating oxygen vacancies that enable ionic activity and conductivity at elevated temperatures. − Oxygen anions and other active species like O and OH – can easily be introduced onto the surface and into the bulk of YSZ through gas exposures or electrochemical pumping. For instance, in the harsh environment gas sensing of the AuNPs/YSZ system, there is a reversible formation and dispersion of oxygen anions in YSZ with the reversible transfer of Au conduction band electrons at the interfacial area to oxygen upon exposure to redox gases, while the plasmonic property changes with the modulation of the free electron density serve as gas sensing signals. − In either H 2 + YSZ + O or H 2 O + YSZ heterogeneous reaction schemes, appreciable amounts of H 2 O are determined to be “absorbed” into the bulk as interstitial hydroxyl and hydrogen species. − In electrochemical membrane reactors or solid-state fuel cells, oxygen anions can be electrochemically generated and pumped through a YSZ electrolyte and participate in chemical reactions. − Given the excellent catalytic activity of AgNPs with their strong plasmonic properties and the ionic activity of YSZ, we decided to perform a functional coupling of bimodal Ag nanoparticles with a nanothin layer of YSZ prepared on quartz substrates, considering that active oxygen species associated with YSZ may interplay with the adsorbates and the nanoparticles, thereby affecting the catalytic redox reactions.…”

Section: Introductionmentioning

confidence: 99%

Ag Nanoparticles Supported on Yttria-Stabilized Zirconia: A Synergistic System within Redox Environments

et al. 2016

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In this work, we report a distinctive dynamic sintering-free redox behavior of Ag nanoparticles (AgNPs) on 30 nm thick yttria-stabilized zirconia (YSZ) films. The material system demonstrates reversible 200 nm shifts in the plasmonic spectra with an unprecedented particle phase/size/morphology oscillation during cyclic redox reactions in air and hydrogen/air at 300−400 °C. This is in significant contrast to the minor changes more commonly observed for AgNPs on quartz. It was found that the ionically active YSZ has a strong tendency to drive AgNPs to oxidize under oxidizing conditions, and upon surface oxidation a large differential surface energy is built up, forcing the core/shell particles to migrate and coalesce toward a lower system free energy. Most strikingly, once switched to a mixture of H 2 and air, the previously formed large dewetted metal-core/thick oxide-shell particles collapse, and new small Ag nanoparticles quickly form and remain in a highly dispersed and sintering-free state on YSZ. This is found to likely be due to catalytic production of water over the material system, which plays a key role in the dynamic redox activities. It is hypothesized that the small metallic particle regeneration and sinter-free behavior take place through a fourstep process resulting from the synergistic behavior of AgNPs supported on YSZ within a redox environment: (I) production of a local humid environment via catalytic reactions of H 2 and O 2 mostly at the triple-phase boundary, (II) dissolution of Ag + from both reduced Ag and the AgO x shell, (III) collapse and spillover of the AgO x shell/water layer with Ag ions onto the hydrous YSZ surface, and (IV) reduction, diffusion, nucleation, and growth to new small metallic AgNPs with a dynamic equilibrium quickly reached. The findings behind this novel system could set up an avenue for a new concept of catalysts operating in a selfcontrolled dynamic regime for governing chemical reactions via metal and ceramic synergized catalysis with high activities and stabilities.

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“…Addition of yttria to zirconia stabilizes its cubic structure. It is known that the supports with this structure are successfully used for catalysts based on zirconia because they improve the properties of the catalyst system [11][12][13]. In addition, the presence of yttria in the zirconia lattice facilitates the increase in oxygen vacancies that improve the oxygen ion conductivity in the solid electrolytes applicable to fuel cells [14].…”

Section: Introductionmentioning

confidence: 99%