Stabilising alumina supported nickel particles against sintering in ammonia/hydrogen atmosphere
Artikel i vetenskaplig tidskrift, 2004

Two different methods to stabilise alumina-supported nickel particles against sintering have been studied. The first investigated method was co-impregnation using precursors of nickel and different promoters (i.e. oxides of Li, Na, K, Mg, Ca, La and Cc) and the second was formation of a protecting nickel aluminate layer between the nickel particles and the gamma-alumina support. The samples were heat-treated in ammonia + hydrogen at 523 K and 250 bar. The sintering process was mainly followed by hydrogen chemisorption. The samples were also characterised by specific surface area measurements, X-ray diffraction and transmission electron microscopy with energy dispersive X-ray mapping. Co-impregnation with oxides of alkali metals, alkaline earths, or lanthanides markedly suppressed the sintering of nickel. The most pronounced effect was achieved for the samples promoted with alkaline earths for which up to 50% of the active surface area remained after the heat-treatment in ammonia + hydrogen compared with the Ni/Al2O3 reference sample. The formation of nickel aluminate by sequential impregnation of the nickel precursors, with calcination at 923 K between the impregnations, enhanced the sintering stability with 35% compared to the reference sample.

catalyst deactivation

Sintering

ammonia

chemisorption

hydrogen

nickel

alumina

promoters

Författare

Johan Lif

Chalmers, Institutionen för material- och ytkemi, Teknisk ytkemi, Keramteknologi

Kompetenscentrum katalys (KCK)

Magnus Skoglundh

Chalmers, Institutionen för material- och ytkemi, Teknisk ytkemi, Keramteknologi

Kompetenscentrum katalys (KCK)

Lars Löwendahl

Chalmers, Institutionen för material- och ytkemi, Teknisk ytkemi, Keramteknologi

Applied Catalysis A: General

0926-860X (ISSN) 1873-3875 (eISSN)

Vol. 274 1-2 61-69

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Energi

Materialvetenskap

Ämneskategorier

Bearbetnings-, yt- och fogningsteknik

Kemiteknik

DOI

10.1016/j.apcata.2004.05.022

Mer information

Skapat

2017-10-07