CuPd Alloy Oxide Nanobelts as Electrocatalyst Towards Hydrazine Oxidation

Abstract

Among non-precious metal catalysts for the hydrazine oxidation reaction, Cu-based catalysts have exhibited relatively high performance ascribed to their lower onset potential and better stability. However, the catalytic properties, including activity and durability, still need further improvement in contrast to noble metal catalysts such as Pt and Pd. In this study, Pd was used as the promotor between Cu and Pd towards the hydrazine oxidation reaction. The CuPd alloy oxide ((Cu 0.9 Pd 0.1 ) O) nanobelts were fabricated by using a dealloying method. The electrochemical measurements show that (Cu 0.9 Pd 0.1 )O nanobelts exhibit 1.5 times higher current density, and better stability than CuO towards the hydrazine electro-oxidation reaction. These improvements are further evidenced in the direct hydrazine-hydrogen peroxide fuel cell by using these two catalysts as the anodes in comparison. A single fuel cell using (Cu 0.9 Pd 0.1 )O as the anode exhibits a peak power density of 330 mW cm À 2 , about 100 mW cm À 2 higher than that of pure CuO. N 2 sorption experiments and product analysis demonstrate that alloying with Pd not only could enlarge the surface area of (Cu 0.9 Pd 0.1 )O but also could suppress the self-decomposition of hydrazine. These improvements will consequently increase the catalytic activity and fuel efficiency of (Cu 0.9 Pd 0.1 )O.

Palladium-Nickel Electrocatalysts on Nitrogen-Doped Reduced Graphene Oxide Nanosheets for Direct Hydrazine/Hydrogen Peroxide Fuel Cells

“…At the same time, the peak potential is moved to more positive values, suggesting an irreversible electrochemical process [57]. Equation (9) describes the relationship between peak potential, E p (V), and sweep rate, v (V s −1 ), for an irreversible electrochemical process [58]:…”

“…N 2 H 4 is considered a promising liquid fuel for the following reasons: (1) its handling is safer; (2) its electrooxidation occurs without the generation of carbon dioxide, which leads to a reduction of greenhouse gas emissions; (3) catalysts are not poisoned during the N 2 H 4 oxidation reaction due to lack of the carbonaceous intermediates production, as reported by Mohammed et al, who investigated the sensitive electrochemical detection of hydrazine based on SnO 2 /CeO 2 nanostructured oxide and reported the high stability, sensitivity and repeatability of hydrazine oxidation on the synthesized nanomaterial [6]; and (4) because of the high theoretical electromotive force of 1.56 V [7] and power density (PD) of 5.4 KWh L −1 observed for DHzHPFCs. On the other hand, a simple internal structure of fuel cells is obtained with an oxidant of hydrogen peroxide (H 2 O 2 ) [8][9][10]. Compared to the oxygen reduction reaction (ORR) with a theoretical electrode potential of 1.23 V, the theoretical electrode potential of the H 2 O 2 reduction reaction (HRR, 1.77 V) and the corresponding kinetics is higher.…”

“…According to Equation ( 3), H 2 O and N 2 are products of this type of DFC [10,11]. Various chemicals have been designed recently and their performances as catalysts examined in the DHzHPFC [3,5,9,[12][13][14][15][16][17][18]. For example, the accumulation of gas bubbles on the electrode surface is effectively solved by using a nano-hill morphology of vertical graphene, by means of which a superoleophobic electrode was obtained that could accelerate the elimination process of bubbles generated on the anodic electrode surface.…”

Development Trends on Nickel‐Based Electrocatalysts for Direct Hydrazine Fuel Cells

“…With these considerations, there is no doubt that direct oxidation of N 2 H 4 with an appropriate electrocatalytic material at reasonable reaction kinetics, if possible, gives multiple advantages. However, the current technology of catalysts for HzOR from both cost and performance standpoints is inadequate to push forward large‐scale commercial and industrial applications [13,26–34] . The kinetic limitations of this reaction increase overpotential and consequently deteriorate the electrode efficiency [35–38] .…”

“…However, the current technology of catalysts for HzOR from both cost and performance standpoints is inadequate to push forward large-scale commercial and industrial applications. [13,[26][27][28][29][30][31][32][33][34] The kinetic limitations of this reaction increase overpotential and consequently deteriorate the electrode efficiency. [35][36][37][38] Hence, designing high performance electrocatalysts for HzOR is an imperative requirement to overcome these challenges.…”