Pt-Ni Nanoalloys for H2 Generation from Hydrous Hydrazine

Abstract

Hydrous hydrazine (N2H4∙H2O) is a candidate for a hydrogen carrier for storage and transportation due to low material cost, high hydrogen content of 8.0%, and liquid stability at room temperature. Pt and Pt nanoalloy catalysts have been welcomed by researchers for the dehydrogenation of hydrous hydrazine recently. Therefore, in this review, we give a summary of Pt nanoalloy catalysts for the dehydrogenation of hydrous hydrazine and briefly introduce the decomposition mechanism of hydrous hydrazine to prove the design principle of the catalyst. The chemical characteristics of hydrous hydrazine and the mechanism of dehydrogenation reaction are briefly introduced. The catalytic activity of hydrous hydrazine on different supports and the factors affecting the selectivity of hydrogen catalyzed by Ni-Pt are analyzed. It is expected to provide a new way for the development of high-activity catalysts for the dehydrogenation of hydrous hydrazine to produce hydrogen.

Enhanced stability of sub-nanometric iridium decorated graphitic carbon nitride for H2 production upon hydrous hydrazine decomposition

“…The selectivity of the process depends upon several reaction conditions, such as pressure, temperature and nature of the catalyst. [55][56][57] Previous studies have shown that iridium is effective in the catalytic decomposition of hydrous hydrazine. Singh and co-workers reported the activity of a series of monometallic nanoparticles (Rh, Co, Ir, Cu, Ni, Fe, Pt and Pd) for the hydrous hydrazine decomposition and, at 298 K, although very active, Ir was only able to achieve 7% of H 2 selectivity, and no information on the stability of the catalysts was reported.…”

Selective decomposition of hydrazine over metal free carbonaceous materials

“…The selectivity of the reaction can vary with the variation of experimental reaction conditions, such as pressure, temperature and the choice of catalyst present. [22][23][24][25] In a typical hydrazine catalytic decomposition process on metal surfaces, the molecule adsorbs on the catalyst surface (below marked with an asterisk) driving the N-N or the N-H cleavage. From a thermodynamic point of view, the cleavage of the N-N bond (eqn (3)) is favored compared to the N-H bond dissociation energy (BDE, eqn (4)).…”

Mn‐Modified Graphitic Carbon Nitride‐Supported Bimetallic PtNi Nanoparticles for Hydrogen Generation from Hydrous Hydrazine

“…Using bimetals as active components can reduce the amount of noble metal Pt. Combining precious metal Pt with non‐precious metal Ni to form an alloy, through alloying modification, the adsorption configuration of reactant molecules and the adsorption strength of catalyst and N 2 H 4 are affected, thereby improving the catalytic performance [33–37] …”

“…Combining precious metal Pt with non-precious metal Ni to form an alloy, through alloying modification, the adsorption configuration of reactant molecules and the adsorption strength of catalyst and N 2 H 4 are affected, thereby improving the catalytic performance. [33][34][35][36][37] For instance, xu et al employed the immobilization of monodispersed PtNi NPs on diamine-alkalized reduced graphene oxide to prepare Pt 0.6 Ni 0.4 /PDA-rGO, which gives TOF value of 2056 h À 1 at 323 K. [38] Luo et al reported the preparation of Ni 88 Pt 12 @MIL-101 via a facile liquid impregnation approach for immobilization of ultrafine bimetallic NiÀ Pt nanoparticles inside the pores of MIL-101 with TOF value of 375.1 h À 1 at 323 K. [39] Luo and co-workers further reported a flower-like NiÀ Pt nanoclusters through a facile wet chemical reduction way, achieving a TOF value of 416 h À 1 at 323 K. [40] Wang et al employed a simple method design and synthesis NiPt/N-doped carbon nanocomposite catalyst, demonstrating excellent catalytic performance for hydrogen generation from hydrazine monohydrate in aqueous solution, which affords TOF values of 1602 h À 1 at 323 K. [7] Meanwhile, besides the catalyst composition, the configuration and characteristic of carrier materials also have a pivotal impact on the improving of catalyst performance. [38] In recent years, g-C 3 N 4 has attracted extensive focus on supported catalytic systems due to its wellsuited band position and excellent thermochemical stability.…”