a	Equilibrium adsorbed amount
BET	Brunauer–Emmett–Teller approach
BJH	Barrett–Joyner–Halenda
CCD	Charge-coupled device
CPS	Counts per second
DC	Direct current
EDX	Energy-dispersive X-ray spectrometer
FEG	Field emission electron gun
fcc	Face centered cubic
FTIR	Fourier transform infrared
GHSV	Gas hourly space velocity
HAADF	High angle annular dark field detector
HRTEM	High-resolution transmission spectroscopy
IUPAC	International Union of Pure and Applied Chemistry
liq.	Corresponding to liquid nitrogen
MP-AES	Microwave plasma atomic emission spectroscopy
P	Pressure
P 0	Vapor pressure
PBI	Polybenzimidazole
PSD	Pore-size distribution
r	Pore radius
SBET	The specific surface area
Smeso	The specific area of mesopores
SEM	Scanning electron microscopy
STEM	Scanning transmission electron microscopy
STP	Standard temperature and pressure (273 K, 101.325 kPa)
T	Temperature
TEM	Transmission electron microscopy
TOF	Turn over frequency
T 50	Temperature corresponding to 50% conversion
T 90	Temperature corresponding to 90% conversion
V	Volume
VOC	Volatile organic compound
vol.	Volume
Vmicro	The specific volume of micropores
Vtot	The specific total pore volume
wt.	Weight
X	Conversion
XPS	X-ray photoelectron spectroscopy
XRD	X-ray diffraction