Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Highly Efficient Fuel Cell Electrodes from Few-Layer Graphene Sheets and
  Electrochemically Deposited Palladium Nanoparticles   An extremely efficient ethanol fuel cell electrode is produced by combining
the large surface area of vertically oriented and highly conductive few-layer
graphene sheets with electrochemically deposited palladium nanoparticles. The
electrodes show an extraordinary high catalyst activity of up to 7977 mA/(mg
Pd) at low catalyst loadings of 0.64 $\mu$g/cm$^2$ and a very high current
density of up to 106 mA/cm$^2$ at high catalyst loadings of 83 $\mu$g/cm$^2$.
Moreover, the low onset potentials combined with a good poisoning resistance
and long-term stability make these electrodes highly suitable for real
applications. These features are achieved by using a newly developed
electrochemical catalyst deposition process exploiting high voltages of up to
3.5 kV. This technique allows controlling the catalyst amount ranging from a
homogeneous widespread distribution of small ($\leq$ 10 nm) palladium
nanoparticles to rather dense layers of particles, while every catalyst
particle has electrical contact to the graphene electrode.

5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
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The categories of this paper are: nlin
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
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The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat