Preliminary studies of platinum dissolution from a spent industrial catalyst

Angelidis, Thomas; Skouraki, E.

doi:10.1016/0926-860x(96)00088-9

Cited by 62 publications

(42 citation statements)

References 4 publications

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“…In general, recycling Pt from products, such as automotive catalysts, is conducted by using a leaching method with chloride-based solutions, such as oxyacids. [1][2][3] The method is technically reliable and applicable to most products, including PEFCs. 4) However, there are some problems with the leaching method, for example, generation of large quantities of acidic waste and corrosion of the materials by strong acid media.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Dissolution of Platinum and Ruthenium from Membrane Electrode Assemblies of Polymer Electrolyte Fuel Cells

Kanamura

Yagyu

2016

Mater. Trans.

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To establish a recovery method for noble metals from membrane electrode assemblies (MEAs) of spent polymer electrolyte fuel cells (PEFCs) without the use of strong acids, electrochemical dissolution tests for Pt and Ru from MEAs were conducted. By using square potential waves, 93.2% of the Pt and 98.4% of the Ru dissolved from a MEA in 1 mol L −1 HCl at room temperature when oxidation and reduction potentials were at 1.5 and 0.1 V vs. SHE and the holding times for both were 15 s per cycle. The dissolution of Pt and Ru became remarkable when the oxidation potential was 1.4 V vs. SHE and gradually decreased at more positive potentials. These results indicate that competitive reactions exist in the dissolution process. In addition, the effects of H + and Cl − concentrations on the dissolution ratios were investigated. The dissolution ratios of Pt and Ru were small in solutions with low Cl ). Thus, we veri ed that the electrochemical dissolution method was adaptable to the recovery of noble metals from MEAs and that strong acids were not needed.

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Section: Introductionmentioning

confidence: 99%

Electrochemical Dissolution of Platinum and Ruthenium from Membrane Electrode Assemblies of Polymer Electrolyte Fuel Cells

Kanamura

Yagyu

2016

Mater. Trans.

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“…Krom terdapat di alam dalam dua bentuk oksida, yaitu Cr(VI) atau chromium hexavalent dan Cr(III) atau chromium trivalent. Cr(VI) mudah larut dalam air dan membentuk divalent oxyanion yaitu kromat (CrO 4 2-) dan dikromat (Cr 2 O 7 2-). Tingkat toksisitas Cr(VI) sangat tinggi sehingga bersifat racun terhadap semua organisme untuk konsentrasi > 0,05 ppm.…”

Section: Pendahuluanunclassified

“…Selain itu juga dipakai sebagai material penahan korosi dalam industri kimia, elektronika, dan industri perawatan kesehatan gigi. Pengolahan limbah Pt dapat dilakukan dengan cara mereduksi Pt (IV) menjadi Pt (0) yang akan terdeposit di permukaan katalis, selanjutnya dapat diambil kembali dalam bentuk Pt murni setelah melewati proses recovery [4].…”

Section: Pendahuluanunclassified

PENGOLAHAN LIMBAH ORGANIK (FENOL) DAN LOGAM BERAT (Cr6+ ATAU Pt4+) SECARA SIMULTAN DENGAN FOTOKATALIS TiO2, ZnO-TiO2, DAN CdS-TiO2 1. Pendahuluan

Slamet¹,

Arbianti²,

Daryanto³

2010

MST

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AbstrakDalam penelitian ini limbah logam berat (Cr dan Pt) dan organik (fenol) diolah secara simultan dengan metode fotokatalitik yang relatif masih baru, kemudian dilanjutkan dengan recovery terhadap logam berat Cr dan Pt. Percobaan fotokatalisis dilakukan meggunakan katalis berbasis TiO 2 dalam fotoreaktor batch. Recovery logam Cr dan Pt masingmasing dilakukan dengan metode presipitasi dan leaching. Hasil penelitian menunjukkan adanya efek sinergisme antara reduksi logam berat (Cr 6+ atau Pt 4+ ) dan oksidasi senyawa organik (fenol) pada sistem fotokatalitik, yaitu dapat meningkatkan konversi masing-masing. Penambahan dopan ZnO (loading optimal = 0,5% berat) dapat meningkatkan kinerja fotokatalis TiO 2 dalam mereduksi Cr(VI), meskipun tidak terlalu signifikan. Loading CdS (pada TiO 2 ) yang optimal adalah sebesar 1% berat, memberikan aktivitas tertinggi dengan konversi reduksi Cr(VI) dan oksidasi fenol masing-masing ≥ 97 % dan 93 %. Reduksi Platinum menggunakan fotokatalis 0,5%ZnO-TiO 2 dan 1%CdS-TiO 2 terbukti cukup efektif dengan konversi > 99 % selama 2 jam reaksi. Proses recovery Cr(III) mencapai hasil optimal pada pH = 9, dengan efisiensi recovery sebesar 91 %. Suhu leaching optimal pada proses recovery Pt adalah 100 o C, dengan efisiensi recovery sebesar 86 %. AbstractSimultaneous Treatment of Organic (Phenol) and Heavy Metal (Cr 6+ or Pt 4+ ) Wastes over TiO 2 , ZnO-TiO 2 and CdS-TiO 2 Photocatalysts. Treatment of heavy metal (Cr 6+ and Pt 4+ ) and organic (phenol) wastes has been studied using the relatively new method, i.e. simultaneous photocatalytic process over TiO 2 photocatalysts in the batch photoreactor. Following the photocatalytic reduction of the heavy metal wastes, recovery of Cr and Pt was carried out by precipitation and leaching method, respectively. The experimental results show that in the simultaneous photocatalytic system, there is a synergism effect between the photocatalytic reduction of heavy metal waste (Cr 6+ or Pt 4+ ) and the oxidation of organic waste (phenol), so that increasing the conversion of each other. Dopant of ZnO with the optimum loading (0.5 wt%) could slightly increase the performance of TiO 2 photocatalyst in photocatalytic treatment of the wastes. Whereas CdS dopant with the optimum loading of 1 wt% could significantly enhance the performance of TiO 2 photocatalyst in simultaneous Cr(VI) reduction and phenol oxidation with the highest conversion of ≥ 97 % and 93 %, respectively. Photocatalytic reduction of Pt(IV) under 0.5%ZnO-TiO 2 and 1%CdS-TiO 2 photocatalysts effectively occurred with a high conversion (> 99 %) in 2 hours irradiation of UV. The optimum precipitation condition of Cr(III) recovery was achieved at pH = 9, with the efficiency of recovery was 91 %. Optimum temperature of leaching process in Pt recovery was 100 o C, with the efficiency of recovery was 86 %.

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“…Nesses casos, procura-se simplificar a composição da amostra e/ou reduzir certos elementos da fase ativa (como os metais nobres) ao estado elementar, enquanto que outros componentes do catalisador (especialmente o suporte) são dissolvidos em meio apropriado (NaOH ou ácidos não oxidantes). Outras rotas prevêem a dissolução total da amostra em meio ácido oxidante [10][11] . Como o suporte corresponde à maior parte em peso do catalisador, o consumo de reagente é considerável, e gera-se muito resíduo.…”

Section: Introductionunclassified