Efficient and selective electrosynthesis of 4-aminophenol at circumneutral pH from the electrocatalytic reduction of nitrophenol over the nickel-iron phosphide modified electrode

Aqueous Electrocatalytic Reduction as a Low‐Carbon and Green Route for Chemical Synthesis and Environmental Remediation

“…Encouraged by these promising results, Lin and his coworkers established a microNiFeP-based flow-type electrocatalytic platform for the electrosynthesis of 4-AP and investigated the e À /H + transfer mechanism behind the electrosynthesis of 4-AP. [11] They found that the 4-AP can be generated at the microNiFeP electrode at the applied potentials more positive than the equilibrium potential of HER (i. e., 0.0 V vs. RHE) (Figure 4), which means that the synthesis of 4-AP from the electrochemical reduction of 4-NP requires lower energy than HER. For example, a noticeable conversion of 4-AP (~3.0 %) with a high Faraday efficiency for 4-AP production (~83.4 %) was achieved after 2-h electrolysis using the prepared micro-NiFeP electrode at 0.1 V vs. RHE in 4-NP (4 mM)-contained phosphate buffer solution (0.5 M, pH 7).…”

“…[36] It d) turnover frequency (TOF AP ). [11] Scheme 2. The proposed reaction pathway for the electrochemical reduction of 4-NPat the CP j microNiFeP (r = 0.5) electrode.…”

“…The proposed reaction pathway for the electrochemical reduction of 4-NPat the CP j microNiFeP (r = 0.5) electrode. [11] was found that trichloroacetic acid has high electrochemical inertness and requires a very high cathodic potential (~À 1.4 V vs. SCE or ~À 0.74 V vs. RHE) to get reduced electrochemically at a bare CNT-modified electrode. Nevertheless, the applied potential (or energy consumption) can be significantly reduced to À 0.4 V vs. SCE (or ~0.26 V vs. RHE) by using a hemoglobinmodified CNT electrode, at which the reduction of trichloroacetic acid proceeded via the indirect electron transfer through the reduction of heme-Fe III active site to form heme-Fe II and subsequent reaction between heme-Fe II and trichloroacetic acid.…”

“…Notably, the electrochemical reduction of nitrophenol to aminophenol can be achieved at applied potentials that are more positive than HER. [11] Finally, a sustainable and carbon-neutral electrochemical reduction process can be realized by its integration with green electricity.…”

“…Figure 4. Electrocatalytic performance of the microNiFeP electrode obtained from 4-h electrolysis in 4-NP (4 mM)-contained phosphate buffer (0.5 M, pH 7): (a) average total current density (Jtotal), average partial current densities for H 2 (J H2 ) and 4-AP (J AP ) generation, (b) Faraday efficiencies (FE) for the generated products, (c) conversion of 4-NP and selectivity for 4-AP production (S AP ), and (d) turnover frequency (TOF AP ) [11]. …”