The reversible hydrogen electrode (RHE) is a reference whose potential is set by the balance between hydrogen gas and the electrolyte's own protons. Because the hydrogen electrode potential changes with pH, potentials reported on the RHE scale are automatically corrected for pH: the RHE potential vs. SHE is −0.0592 × pH volts at 25 °C. Results for HER/OER/ORR obtained in acidic and alkaline electrolytes can therefore be compared directly.

In this product the electrode has no internal electrolyte; according to the manufacturer's description there is no ion leakage or diffusion potential, and hydrogen is supplied by a replaceable generator. The body is PTFE and it contains no heavy metals. According to the literature the RHE is most stable in strongly acidic or alkaline solutions; near neutral pH the hydrogen reaction is slow, so frequent calibration is needed.

Key Features

pH-dependent potential: results on the RHE scale can be compared across electrolytes of different pH
No internal electrolyte: according to the manufacturer there is no ion leakage or diffusion potential
Hydrogen is supplied by a replaceable generator (10101-1)
No electrolyte refilling is required
Heavy-metal-free, made of PTFE; usable in fluorine-containing concentrated media
Designed for concentrated acidic and alkaline media (manufacturer's working range: pH 2 to pH 16)
Can be separated from the test solution with a separately ordered salt bridge (10101-2)

Technical Specifications

Electrode type	Reversible hydrogen reference electrode (RHE): 2H⁺ + 2e⁻ ⇌ H₂
Potential (vs. SHE, 25 °C)	E(RHE) = −0.0592 × pH V (for 1 atm H₂)
Conversion to RHE scale	E(RHE) = E(measured vs. another reference) + E(reference vs. SHE) + 0.0592 × pH
Body material	PTFE; heavy-metal-free
Internal electrolyte	None; no electrolyte refilling required
Working range (manufacturer)	pH 2 to pH 16; effective in concentrated acidic and alkaline media
Hydrogen source	Replaceable hydrogen generator (10101-1)
Salt bridge	Can be separated from the test solution with the 10101-2 salt bridge
Set components	RHE electrode, hydrogen generator, salt bridge (can be ordered separately)
Limitation	Near neutral pH the exchange current of the hydrogen reaction is low; the potential can drift and frequent calibration is needed
Calibration	For accuracy, compare the RHE periodically against a fixed reference such as Ag/AgCl
Unsuitable media	Non-aqueous (organic) electrolytes; the RHE is a water/proton-based system

Available Options

Model	Description
10101 RHE Electrode	Reversible hydrogen electrode
10101-1 Hydrogen Generator	Hydrogen gas generator for the electrode
10101-2 Salt Bridge	Salt bridge for the RHE electrode

For sizes and specifications not listed above, you can request a custom quotation through the Quote Form.

Applications

Electrocatalysis studies that need pH-independent comparison (RHE scale)
Hydrogen/oxygen reaction (HER/OER/ORR) research in acidic and alkaline media
Fuel cell and water electrolysis testing
Concentrated acidic/alkaline electrolyte studies where halide or metal ion contamination must be avoided
Calibration of other reference electrodes against the RHE