Catalytic surface development of novel nickel plate catalyst with combined thermally annealed platinum and alumina coatings for steam methane reforming

Catalytically active surface of small nickel (min 99 wt%) plates for steam methane reforming was enhanced by successive temperature programmed oxidation−reduction (TPO−TPR) pretreatment and combined physical vapor deposition of Pt and Al2O3. The effect of annealing time, temperature, order and number of coatings on the catalytic activity was investigated by means of a pulse technique at the reaction temperature of 760 °C. The most active and stable surface phases resulted after the successively deposited layers of Pt, Al2O3, and Pt had been annealed for 12 h onto 2-cycle TPO−TPR pretreated nickel plate at the temperature of 700 °C in a circulating atmosphere of N2. The durability performance of the so-prepared surface phases on a specifically structured plate catalyst element (diameter 43 mm and length 42 mm) was tested in a tubular reactor for some 70 h in temperature range 500−650 °C. Deactivation was mainly caused by carbon surface deposition.