Transition Metal Oxide Electrocatalysts for Ambient Ammonia Synthesis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The Haber-Bosch process for ammonia production is energy-intensive and greenhouse gas-emitting, necessitating the development of a greener, energy-efficient alternative for ammonia synthesis.
Innovation Solution
An electrocatalyst comprising transition metal oxides, such as RuO2 and PdO, is used to electrochemically reduce nitrogen and nitrogen oxides to ammonia at ambient conditions, with optional support from conductive materials and co-catalysts like metal-phthalocyanine dyes, facilitating ammonia synthesis in an electrochemical cell under controlled voltage and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the Haber-Bosch process is used for ammonia production, then ammonia can be synthesized, but very high pressure and temperature are required and greenhouse gas emissions occur
Solution Approach 1:
The patent changes the operating parameters from high temperature and pressure (Haber-Bosch) to ambient temperature and pressure (electrocatalytic process). The electrocatalyst enables nitrogen reduction at significantly milder conditions, eliminating the need for energy-intensive high temperature and pressure while preventing greenhouse gas emissions.
Solution Approach 2:
The patent replaces the mechanical/thermal system (Haber-Bosch process using high pressure and temperature) with an electrochemical system (electrocatalytic nitrogen reduction). This substitution uses electrical energy to drive the reaction at ambient conditions, eliminating the mechanical compression and thermal heating required by traditional methods.
2Quantity of substance
If steam reformation is used to generate hydrogen, then hydrogen is produced, but three to five percent of total natural gas production is consumed and greenhouse carbon dioxide is released
Solution Approach 1:
The electrocatalyst performs multiple functions: it reduces nitrogen to ammonia directly and can also reduce nitrate/nitrite to ammonia. This self-service capability eliminates the need for separate hydrogen production and nitrogen fixation steps, thereby avoiding the harmful effects of steam reformation while maintaining ammonia synthesis efficiency.
Solution Approach 2:
The patent extracts the harmful step (steam reformation) from the ammonia synthesis process by using electrocatalytic nitrogen reduction that does not require hydrogen from steam reformation. The electrocatalyst directly converts nitrogen to ammonia, removing the source of greenhouse gas emissions from the process chain.
3Temperature
If transition metal oxides are used as electrocatalysts, then ammonia synthesis occurs at ambient conditions, but the catalyst must be devoid of iron oxide, TiO2, and elemental metals to achieve high electrocatalytic activity
Solution Approach 1:
The patent applies local quality by specifying particular transition metal oxides (RuO2, PdO, and their combinations) with defined compositions and structures. The electrocatalyst has specific compositional characteristics (devoid of certain materials, containing reactive oxygen species) that enable ambient temperature operation while maintaining high activity, resolving the contradiction between mild conditions and catalyst complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The electrocatalyst achieves ammonia synthesis at ambient pressure and temperature with high electrocatalytic activity, producing ammonia at rates of 1×10−11 mol cm−2 s−1 and faradaic efficiencies above 30%, offering a more sustainable alternative to traditional methods.
Implementation Method 1
the electrocatalyst achieves ammonia synthesis at ambient pressure and temperature with high electrocatalytic activity, producing ammonia at rates of 1×10−11 mol cm−2 s−1 and faradaic efficiencies above 30%
Implementation Method 2
An electrocatalyst comprising transition metal oxides, such as RuO2 and PdO, is used to electrochemically reduce nitrogen and nitrogen oxides to ammonia at ambient conditions, with optional support from conductive materials
Implementation Method 3
the outer surface of the transition metal oxide comprises a plurality of reactive oxygen species; optionally wherein the reactive oxygen species are selected from singlet oxygen, a peroxide, a superoxide, a hydroxyl radical or any combination thereof
Data Source
AI summary
Electrocatalysts comprising transition metal oxide are disclosed. Uses the electrocatalyst as a working electrode are further disclosed. Electrochemical cells containing the working electrode and use thereof in the process of synthesizing ammonia is further disclosed.