The effects of iron addition to Pd/C and Pd+Pt/C catalysts on the selective hydrogenation of nitric acid in the presence of GeO2

Hara, Takuma; Nakamura, Yosuke; Nishimura, Jun

doi:10.1016/j.apcata.2007.01.028

Cited by 4 publications

(2 citation statements)

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“…3 Fe-Pd is also studied as a good catalytic system. 4 Structurally, Fe-Pd is an interesting alloy system. Unlike the all-paramagnetic all-fcc (e.g., Cu-Au) or the all-bcc (e.g., Mo-Ta) alloys, Fe-Pd exhibits (see Fig.…”

Section: Introductionmentioning

confidence: 99%

Ab initiotheory of phase stability and structural selectivity in Fe-Pd alloys

2012

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In Fe-Pd alloys, the competing geometric (fcc versus bcc) and magnetic tendencies result in rich phase stability and ordering physics. Here, we study these alloys via a first principles mixed-basis cluster expansion (CE) approach. Highly accurate fcc and bcc CEs are iteratively and self-consistently constructed using a genetic algorithm, based on the first principles results for ∼100 ordered structures. The structural and magnetic "filters" are introduced to determine whether a fully relaxed structure is of fcc/bcc and high-/low-spin types. All structures satisfying the Lifshitz condition for stability in extended phase diagram regions are included as inputs to our CEs. We find that in a wide composition range (with more than 1/3 atomic content of Fe), an fcc-constrained alloy has a single stable ordered compound, L1 0 FePd. However, L1 0 is higher in energy than the phase-separated mixture of bcc Fe and fcc-FePd 2 (β2 structure) at low temperatures. In the Pd-rich composition range, we find several fcc β2-like ground states: FePd 2 (β2), Fe 3 Pd 9 , Fe 2 Pd 7 , FePd 5 , Fe 2 Pd 13 , and FePd 8 , yet we do not find FePd 3 with the the experimentally observed L1 2 structure. Fcc Monte Carlo simulations show a transformation from any of the attempted β2-like ground states directly into a disordered alloy. We suggest that the phonon and/or spin excitation contributions to the free energy are responsible for the observed stability of L1 2 at higher temperatures, and likely lead to a β2 ↔ L1 2 transition. Finally, we present here a complete characterization of all the fcc and bcc Lifshitz structures, i.e., the structures with ordering vectors exclusively at high-symmetry k points.

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Section: Introductionmentioning

confidence: 99%

Ab initiotheory of phase stability and structural selectivity in Fe-Pd alloys

2012

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“…Chemical reduction of nitrates 60-70 80-85 [15] Route 1 is rejected because it introduces the element sulfur, which is not consumed or produced in the reaction. Besides data on yields, conversions, and selectivity, the amount of information available for a proper process design is also an important factor in this stage of process design.…”

Section: Chemical Routesmentioning

confidence: 99%

Industrial Process Design for the Production of Aniline by Direct Amination

et al. 2017

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The objective is to design a plant from raw material to product for the production of aniline by direct amination of benzene. The process design is started on a conceptual level and ended on a basic engineering level as well as a techno‐economical evaluation. The amination of benzene by hydroxylamine was used as basis. For the production of hydroxylamine four routes are proposed. The most promising route is the chemical reduction of nitric oxide with hydrogen. The process evaluation shows that 27 % of the atomic nitrogen is lost. The atomic carbon efficiency is close to unity. Furthermore, a significant amount of steam can be produced. From an economical perspective, there is still room for improvement because the return of investment is quite low and the payback period is quite high.

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