A vacuum cleaner comprises a cylconic separation unit with a dirty air inlet and a cleaned air outlet at a first end and a dirt collection portion at a second end. Catalyst carrier particles having a catalyst substance 10 carried on the surface of electron conductive particles 1, and a polymer electrolyte containing catalyst having a catalyst substance 20 dispersed in an ion conductive polymer 2 coexist. The device further includes a plurality of vanes extending from an inner surface of the passageway and spaced apart from one another and disposed upstream of a discontinuity in the exhaust pipe. The first hydroisomerization catalyst has a first level of selectivity for the isomerization of n-paraffins, the second hydroisomerization dewaxing catalyst has a second level of selectivity for the isomerization of n-paraffins, and a layered catalyst system comprising the first and second hydroisomerization dewaxing catalysts has a third level of selectivity for the isomerization of n-paraffins.