Heteroatom doped 3D graphene aerogel supported catalysts for formic acid and methanol oxidation

Çögenli, M. Selim; Yurtcan, Ayşe Bayrakçeken

doi:10.1016/j.ijhydene.2019.10.226

Cited by 52 publications

(19 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Platinum or Pd nanoparticles supported on heteroatom doped 3D graphene aerogel was tried for formic acid and methanol oxidation 27,28 , while the performance was still not satisfactory because of insufficient oxophilic species formation. By coupling the above inspirations, herein, we tried to fabricate the hybrid PdNi/graphene aerogel (PdNi/GA) catalyst by a simple freezingdrying/annealing approach to probe the formic acid oxidation ability.…”

Section: Introductionmentioning

confidence: 99%

Formic Acid Electro-oxidation Catalyzed by PdNi/Graphene Aerogel

Bao¹,

Feng²

2020

Acta Physico Chimica Sinica

View full text Add to dashboard Cite

Direct formic acid fuel cells involve two significant half-reactions, namely formic acid electro-oxidation and oxygen reduction reaction, and the more sluggish and complex process for anode formic acid oxide also determine the whole fuel cells energy conversion efficiency. The most efficient catalysts rely on the noble metal of Pt and Pd based catalysts and compared with Pt catalysts, Pd catalyst is more appealing because of the low CO poisoning effect during the electro-oxidation of formic acid that mainly follows the direct pathway. The Pd alloy effect and support effect should be considered for the catalyst fabrication since the resulted structure and electronic modification could largely increase the catalytic performance. Graphene emerges out as novel support while the easy agglomeration and destruction of pure graphene do not guarantee promising merits. In this work, we demonstrated the formic acid oxidation ability boosting by facile coupling PdNi alloy and 3D graphene aerogel (PdNi/GA) via a freezingdrying/thermal annealing reduction approach. The PdNi alloy crystal structure was well confirmed by the X-ray diffractions technique and the alloy nanoparticles were successfully anchored on the 3D graphene aerogel surface. The electrochemical performance was evaluated for formic acid oxidation in the acid electrolyte. The PdNi/GA catalyst displayed a larger peak current density of 136 mA•cm −2 , which was 2 and 3.45 times greater than Pd/GA (68 mA•cm −2 ) and Pd/C (39.4 mA•cm −2 ), respectively. The anti-CO poisoning ability was measured by CO stripping technique, and a low onset potential of 0.49 V was found on PdNi/GA catalyst, about 120 mV less than that of Pd/GA catalyst, indicating the oxophilic property of Ni to assist formic acid oxidation via the bi-functional mechanism. The oxidation peak potential of 0.67 V was observed on PdNi/GA, about 40 mV less than that of Pd/C catalyst, indicating the merits of 3D structure of graphene. Moreover, PdNi/GA catalyst had the highest mass activity of 1699 mA•mg −1 compared to Pd/GA (851 mA•mg −1 ) and Pd/C (537 mA•mg −1 ) catalysts. The specific activity of PdNi/GA was 2.6 mA•cm −2 , which was 1.94 and 2.7 times of Pd/GA (1.34 mA•cm −2 ) and Pd/C (0.96 mA•cm −2 ) catalysts. The highly improved catalytic performance could be due to the combined alloy and support effect. The PdNi/GA was a promising catalyst for application in the direct formic acid fuel cells.

show abstract

Section: Introductionmentioning

confidence: 99%

Formic Acid Electro-oxidation Catalyzed by PdNi/Graphene Aerogel

Bao¹,

Feng²

2020

Acta Physico Chimica Sinica

View full text Add to dashboard Cite

show abstract

“…The anodic and cathodic peak current rate of methanol oxidation on Pt/C catalyst decreased with increasing the methanol concentration. A lower ratio represents much CO molecules are adsorbed on the catalyst which indicates worse oxidation of methanol [24]. It can be assumed that the increment is due to the presence of a diffusion-controlled process that appears to play an important role at low concentrations [25].…”

Section: Resultsmentioning

confidence: 99%

Formic Acid and Methanol Oxidation for Pt/C Catalyst Depending on Rotating Speed, Scan Rate and Concentration

Yurtcan

2019

BEN

View full text Add to dashboard Cite

The oxidation of small organic molecules on the catalyst under electrocatalytic conditions is important for the operation of liquid feed fuel cells. The basic reaction mechanisms toward the oxidation of methanol and formic acid continue to be a matter of debate under real operational conditions of electrochemical systems. The electrocatalytic activity of the commercial Pt/C catalyst was investigated in sulfuric acid/methanol and sulfuric acid/formic acid mixtures using electrochemical measurements. This work presents the variation of formic acid and methanol oxidation on the catalyst depending on hydrodynamic conditions using the rotating disk electrode. Cyclic voltammograms were obtained at different scan rates, rotating speeds and concentrations. As the rotating speed increases, the oxidation activity of formic acid and methanol decrease under voltammetric measurements. The peak currents of formic acid and methanol oxidation increased with the increase in the scan rate and concentration.

show abstract

“…However, in the past, most of the available carbon-based support materials, such as activated carbon and CB, displayed a wide pore size distribution and it was very difficult to reveal the specific relationship between pore size and electrochemical behaviors. Accordingly, CA can be introduced as promising investigation objects because of their relatively narrow and adjustable pore size distribution [63,66,67]. Moreover, CA can be a promising support for PEMFC electrocatalysts mainly because of their unique 3D network structure formed by 3D linked carbon nanoparticles [53,68,69].…”

Section: Pore Sizementioning

confidence: 99%

“…Moreover, CA can be a promising support for PEMFC electrocatalysts mainly because of their unique 3D network structure formed by 3D linked carbon nanoparticles [53,68,69]. Their porous structure can be easily tailored by adjusting the sol-gel synthesis parameters, for example, reactant concentration, catalyst amount, reaction temperature, and time [67]. Yi et al [70] prepared CA microsphere supports with an adjustable pore size using PEG-200 as a template.…”

Section: Pore Sizementioning

confidence: 99%