Elsevier

Journal of Molecular Liquids

Volume 280, 15 April 2019, Pages 274-284
Journal of Molecular Liquids

Review
Advances in iridium nano catalyst preparation, characterization and applications

https://doi.org/10.1016/j.molliq.2019.02.050Get rights and content

Highlights

  • Describes importance of iridium nano-catalysts.

  • Discuss preparation and characterization of iridium nano-catalysts.

  • The applications of iridium nano-catalysts.

  • Futurec challenges and perspectives of iridium nano-catalysts.

Abstract

The present article defines the state-of-the-art of iridium nano catalyst. In this article, the attempts are made to discuss the syntheses, characterizations, applications, toxicity and future perspectives aspects. Over all, the available information on nano iridium catalyst is included in this article. The most important applications of nano iridium catalyst are water splitting, hydrogen and oxygen generation, chemical reactions, fuel cells, sensors (detection), absorption and some other miscellaneous. The growth of the research papers and applications of iridium nano catalyst indicated bright future in various industrial applications. It was observed that iridium nano catalysts are not fully developed and under their development stages. Certainly, these nano materials will be very valuable in a wide range of scientific and industrial applications in near future.

Introduction

Among top nine rare elements, iridium (Ir) is of the utmost importance in various chemical reactions. Generally, it is found in nature as native element or in the form of alloys. The important alloys are iridosmium (iridium rich), osmium iridium alloys and osmiridium (osmium rich). Maximum iridium is found in Canada, Russia and South Africa. The element was discovered by Smithson Tennant in 1803 and its name is founded on name of Greek Goddess ‘Iris’, that symbol is a ‘Rainbow’. Its catalytic activities were discovered by Lauri Vaska in 1960 [1]. It is the most active and widely used catalyst in several reactions both in basic and acidic medium [2,3]. Iridium and its complexes are utilized as homogeneous catalysts, bio-catalyst and nano-catalyst. It is most essential element of platinum group elements with wide array of oxidation positions i.e. -3 to +9 among all transition elements. Due to these facts, iridium has a wide range of uses including catalytic, medical and industrial [[4], [5], [6], [7]]. In photosynthesis process, it is responsible for cracking of water molecules into hydrogen and oxygen [[8], [9], [10]]. Therefore, iridium may be useful in solving food crises by artificial photosynthesis and energy crisis by splitting water generating hydrogen fuel (green energy).

Among various applications, catalytic action is the most significant area of iridium and its complexes for many industrial production including allylic substitution, hydrogen-transfer reactions, hydrogenation, functionalization of Csingle bondH bonds, catalyzed fine chemical synthesis, 1,3-dipolar cycloadditions, etc. For long time iridium and its complexes are used as good catalysts but after the development of nanotechnology the application of this element has increased many folds. This due to the remarkable features of nanoparticles; particle size, charges, free energies etc. [[11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26]] Some authors prepared nano size materials of native iridium and its compounds and used for multi-purposes [[27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42]]. The applications of nano size of iridium and its complexes are found to be remarkable with good number of publications. There is no review article on iridium based catalyst with nano concept. Because of a good growth of the research and publications and lack of review on this topic it was realized to write a review article on advances in iridium catalyst: a nano concept. The details on the synthesis, characterization, application and future perspectives are highlighted in this article. Certainly, this article will be highly useful for academicians, researchers and industrial persons.

Section snippets

Preparation

The preparations of iridium nano particles catalysts were reported by general wet chemistry methods. The various methods involved the iridium salts as the precursors. The different conditions were used by various workers. The particle sized was controlled by the experimental conditions. The nano particle catalysts were separated from reaction mixture and washed numerous times with water. Some authors washed these by alcohol. It is not possible to describe all the reported procedures. However,

Characterization

The iridium nano particle catalysts were characterized by the well-known techniques used in general nano technology. The important techniques are transmission electron microscopy (TEM), scanning electron microscope (SEM), cyclic voltammetry (CV), X-ray diffraction (XRD), electrochemically active surface area (ECSA), atomic force microscope (AFM), field ion microscope (FIM), scanning Tunneling Microscope (STM), scanning probe microscopy (SPM), energy-dispersive analysis of x-rays (EDAX), Fourier

Applications

Iridium is an important element with remarkable properties. Iridium and its complexes have extensive choice of applications in numerous area of science and technology. As a catalysis iridium is an excellent element for catalyzing various organic and inorganic reactions. It is very difficult to write the whole applications of iridium nano catalysts. However, the attempts are made to summarize some important applications so that the readers may be benefited.

Toxicity

As such iridium is not toxic as there is no report on the iridium toxicity in the literature but nano particles of non-biodegradation nature are toxic. Therefore, all the toxicity aspects of nano particles will be applicable to iridium nano particles as these nano particles are non-biodegradable. The non-biodegradable nano particles are threat to human beings and environment. The lesser size of nanoparticles creates their entrance stress-free into the living organisms. Nanoparticles have higher

Future perspectives

As discussed above iridium catalyst has an extensive range of applications and really it is the best element to produce more smart catalyst. The special features of nano particles made this element of extraordinary importance. Much work has not been done to develop the efficient iridium nano particles; especially in water splitting for hydrogen generation – a need of future. Besides, the applications of iridium nano particles are not fully developed in other areas of research and industrial

Conclusion

This review article presents the state-of-the-art of iridium nano catalysts. In this article, the attempts are made to discuss the syntheses, characterizations, applications, toxicity and future perspectives aspects. Over all, the available information on nano iridium catalysts is included in this article. The data included in this article is of great importance for researchers, academicians and industrial persons. The growth of papers and applications of iridium nano catalysts indicated bright

References (115)

  • I. Ali et al.

    Modeling of fenuron pesticide adsorption on CNTs for mechanistic insight and removal in water

    Environ. Res.

    (2019)
  • O.M.L. Alharbi et al.

    Health and environmental effects of persistent organic pollutants

    J. Mol. Liq.

    (2018)
  • E.A. Burakova et al.

    Novel and economic method of carbon nanotubes synthesis on a nickel magnesium oxide catalyst using microwave radiation

    J. Mol. Liq.

    (2018)
  • A.A. Basheer

    Chemical chiral pollution, impact on the society and science and need of the regulations in the 21st century

    Chirality

    (2018)
  • A.A. Basheer

    New generation nano-adsorbents for the removal of emerging contaminants in water

    J. Mol. Liq.

    (2018)
  • H.Y. Aboul-Enein et al.

    Determination of tadalafil in pharmaceutical preparation by HPLC using monolithic silica column

    Talanta

    (2005)
  • H.Y. Aboul-Enein et al.

    Comparative study of the enantiomeric resolution of chiral antifungal drugs econazole, miconazole and sulconazole by HPLC on various cellulose chiral columns in normal phase mode

    J. Pharm. Biomed. Anal.

    (2002)
  • I. Ali et al.

    Speciation of arsenic and chromium metal ions by reversed phase high performance liquid chromatography

    Chemosphere

    (2002)
  • R. Badam et al.

    Synthesis and electrochemical analysis of novel IrO2 nanoparticle catalysts supported on carbon, nanotube for oxygen evolution reaction

    Int. J. Hydrog. Energy

    (2018)
  • M. Blanco et al.

    Effect of structural differences of carbon nanotubes and graphene based iridium-NHC materials on the hydrogen transfer catalytic activity

    Carbon

    (2016)
  • T. Miyao et al.

    Mechanistic study of hydrogen occlusion in hollow silica nano-spheres encapsulating iridium metal clusters

    J. Mol. Catal. A Chem.

    (2013)
  • T. Audichon et al.

    Preparation and characterization of supported RuxIr(1-x)O2 nano-oxides using a modified polyol synthesis assisted by microwave activation for energy storage applications

    Appl. Catal. B Environ.

    (2017)
  • L. Ma et al.

    High halogenated nitrobenzene hydrogenation selectivity over nano Ir particles

    Chin. J. Chem. Eng.

    (2017)
  • T. Yang et al.

    Palladium–iridium nanocrystals for enhancement of electrocatalytic activity toward oxygen reduction reaction

    Nano Energy

    (2016)
  • J. Zhang et al.

    Iridium nanoparticles anchored on 3D graphite foam as a bifunctional electrocatalyst for excellent overall water splitting in acidic solution

    Nano Energy

    (2017)
  • J.G. Oh et al.

    The inhibition of electrochemical carbon corrosion in polymer electrolyte membrane fuel cells using iridium nanodendrites

    Int. J. Hydrog. Energy

    (2012)
  • T. Goto et al.

    Electrochemical properties of iridium-carbon nano composite films prepared by mocvd

    Scr. Mater.

    (2001)
  • S. Kundu et al.

    Shape-selective formation and characterization of catalytically active iridium nanoparticles

    J. Colloid Interface Sci.

    (2011)
  • R.S. Chen et al.

    Growth and characterization of iridium dioxide nanorods

    J. Alloys Compd.

    (2004)
  • J.A. Sawicki et al.

    193Ir Mössbauer spectroscopy of Pt–IrO2 nanoparticle catalysts developed for detection and removal of carbon monoxide from air

    Nucl. Inst. Methods Phys. Res. B

    (2010)
  • M. Zeng et al.

    Remarkable durability of PteIr alloy catalysts supported on graphitic carbon nanocages

    J. Power Sources

    (2014)
  • J. Zhang et al.

    Nanofibers doped with a phosphorescent iridium complex: synthesis, characterization, and photophysical property study

    Synth. Met.

    (2011)
  • H. Ziaei-azad et al.

    Size- and structure-controlled mono- and bimetallic Ir–Pd nanoparticles in selective ring opening of indan

    J. Catal.

    (2013)
  • X. Zeng et al.

    Doped reduced graphene oxide mounted with IrO2 nanoparticles shows significantly enhanced performance as a cathode catalyst for Li-O2 batteries

    Electrochim. Acta

    (2016)
  • H. Jin et al.

    Lanthanide metal-assisted synthesis of rhombic dodecahedral MNi (M = Ir and Pt) nanoframes toward efficient oxygen evolution catalysis

    Nano Energy

    (2017)
  • S.D. Ghadge et al.

    First report of vertically aligned (Sn, Ir) O2: F solid solution nanotubes: highly efficient and robust oxygen evolution electrocatalysts for proton exchange membrane based water electrolysis

    J. Power Sources

    (2018)
  • S. Siracusano et al.

    Nanosized IrOx and IrRuOx electrocatalysts for the O2 evolution reaction in PEM water electrolysers

    Appl. Catal. B Environ.

    (2015)
  • B. Sen et al.

    Bimetallic palladiumeiridium alloy nanoparticles as highly efficient and stable catalyst for the hydrogen evolution reaction

    Int. J. Hydrog. Energy

    (2018)
  • H. Yu et al.

    Nano-size IrOx catalyst of high activity and stability in PEM water electrolyzer with ultra-low iridium loading

    Appl. Catal. B Environ.

    (2018)
  • E. Redel et al.

    Synthesis of co, Rh and Ir nanoparticles from metal carbonyls in ionic liquids and their use as biphasic liquid–liquid hydrogenation nanocatalysts for cyclohexene

    J. Organomet. Chem.

    (2009)
  • R.M. Esteban et al.

    Iridium@graphene composite nanomaterials synthesized in ionic liquid as re-usable catalysts for solvent-free hydrogenation of benzene and cyclohexene

    Nano-Struc. Nano-Obj.

    (2015)
  • Y. Ha et al.

    Alteration of the morphology and electrocatalytic activity of IrO2 nanowires upon reduction by hydrogen gas

    Sensors Actuators B Chem.

    (2015)
  • K.B. Akshaya et al.

    Electrocatalytic oxidation of morin on electrodeposited Ir-PEDOT Nanograins

    Food Chem.

    (2019)
  • Y.G. Ji et al.

    Naked iridium(IV) oxide nanoparticles as expedient and robust catalysts for hydrogenation of nitrogen heterocycles: remarkable vicinal substitution effect and recyclability

    Adv. Synth. Catal.

    (2017)
  • Y. Tonbul et al.

    Iridium(O) nanoparticles dispersed in zeolite framework: a highly active and long-lived green nanocatalyst for-the hydrogenation of neat aromatics at room temperature

    Appl. Catal. B Environ.

    (2014)
  • S.J. Kim et al.

    Electrospun iridium oxide nanofibers for direct selectiveelectrochemical detection of ascorbic acid

    Sensors Actuators B Chem.

    (2014)
  • S.M.A. Shibli et al.

    TiO2 supported Nano IrO2 composite incorporated Ni-P coating for sensing ethanol

    Proc. Technol.

    (2016)
  • Q. Gao et al.

    Enhanced formaldehyde sensing properties of IrO2-loaded porous foam-like Ga1.4In0.6O3 nanofibers with ultrathin pore walls

    J. Alloys Compd.

    (2018)
  • F.D. Kong et al.

    Chun-Yu Du, Pt/porous IrO2 nanocomposite as promising electrocatalyst for unitized regenerative fuel cell

    Electrochem. Commun.

    (2012)
  • D. Dang et al.

    In situ construction of Ir@Pt/C nanoparticles in the cathode layer of membrane electrode assemblies with ultra-low Pt loading and high Pt exposure

    J. Power Sources

    (2017)
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