Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

OP-IV-13HYDROGEN PRODUCTION VIA METHANE DECOMPOSITION ONRANEY-TYPE CATALYSTSA.F. Cunha, J.J.M. Órfão, J.L. FigueiredoLaboratório de Catálise e Materiais, Departamento de Engenharia Química,Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto,Portugal, Fax: +351 225081449, E-mail: jlfig@fe.up.ptAbstractPure hydrogen and filamentous carbon (carbon nanofibres and nanotubes) were producedby catalytic methane decomposition on Raney-type catalysts (Ni, Co and Fe). Conversionsnear to equilibrium were obtained under well defined operating conditions without anysignificant catalyst deactivation.IntroductionConcerns over the environment and depletion of fossil fuels led to the concepts of«hydrogen-energy system» and «hydrogen economy». Hydrogen is a convenient energycarrier which can be used efficiently and without any emissions in fuel cells. Hydrogen ismostly produced by steam reforming of methane, which also yields CO and CO 2 . For fuel cellapplications, however, very low levels of carbon oxides are tolerated. An interestingalternative process is the catalytic decomposition of methane (CH 4 C + 2 H 2 ), especiallyif the carbon by-product can be obtained in suitable form for practical applications [1], suchas carbon nanofibres or nanotubes. Thus, there has been an intense research effort on thistopic in recent years [2, and references therein]. Supported metal catalysts have been mostlyused for this purpose, but in the present work we report promising results obtained withmassive catalysts (Raney-type Ni, Co and Fe).ExperimentalThe Raney-type catalysts were prepared from Me-Al alloys (Me = Ni, Co or Fe) withnominal active phase content in the alloys of 50 or 30 wt. %. The Ni50 alloy was a FlukaChemie GmbH product, and the remaining alloys were supplied by H.C. Starck GmbH. TheNi30 and Co30 alloys were prepared by a patented quenching process [3]. The alloys wereactivated by leaching out Al with a concentrated NaOH solution. The catalysts were tested ina fixed bed reactor either isothermally or under a temperature programme. The original alloys,the resulting catalysts and the carbon deposits were characterized by appropriate techniques.164