Silver catalysts with three different metal loadings e.g. 10, 20 and 40 wt% were synthesised on carbon nanotubes (Ag/CNT) support by glycerol reduction method. The catalysts were characterised by X‐ray diffraction, electron microscopy and thermogravimetric analysis. The average crystalline size of Ag was found between 10 and 16 nm for the metal loading from 10 to 40 wt%. The catalytic activity towards oxygen reduction reaction (ORR) in alkaline solution was studied for the Ag/CNT catalysts in terms of mass activity as well as specific activity. Cyclic voltammetry and rotating disc electrode studies showed higher current density for 40 wt% Ag/CNT catalyst, which maintained suitable durability in potential sweeping cycling in comparison to 10 and 20 wt% Ag/CNT. The fuel cell studies of the synthesized catalysts were conducted using an anion exchange membrane, and all the three Ag/CNT catalysts showed open circuit voltage above 1 V with 40 wt% Ag/CNT gave the highest peak power density of 26.1 mW cm−2 at room temperature, in good agreement with the kinetic data obtained from the half‐cell studies.

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The issue of environmental pollution from diesel engines is a cause of major concern, even though diesel engines provide high thermal efficiency. This problem can be reduced to an extent through the use of modified fuel and catalytic converters. This study focus on improving the energy density of fuel by blending it with metal particles and hence increasing the thermal efficiency and ignition within the combustion chamber. Diesel was blended with nano and micron aluminium particles separately using ultrasonicator. Sorbitan monooleate was used as the surfactant. The catalytic converter was developed by making modification inside the silencer by placing stacks of mesh, which were coated with zeolite copper oxide nanocomposite. The nanocomposite matrix was prepared using copper nitrate solution and zeolite powder in an alcoholic medium, treated with a reducing agent. Engine performance test was carried out separately for both nano and micron aluminium blended diesel in a single cylinder four stroke, air cooled, direct injection Kirloskar engine. The experiment was carried out by varying the load at a constant speed of 1500 rpm to evaluate the performance characteristics. Emissions from the diesel generator fuelled by diesel and modified fuels were recorded by OPAX gas analyser both in the presence and absence of catalytic converter. The results indicated an increase in brake thermal efficiency by 8% and 72% for micro Al blended diesel and nano Al blended diesel respectively, in comparison with ordinary diesel. The emission test using catalytic converter gave 50%, 34% and 17% decrease in CO emission for ordinary diesel, micro-Al blended diesel and nano Al blended diesel respectively.