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[Rare Earth Science] collect quickly! Second understand rare earth catalytic materials

2020-04-24 16:54:09
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Rare earth catalytic materials



Rare earth elements have the characteristics of 4f orbitals not filled with electrons and lanthanide contraction, which show good catalytic performance, so they are used as excellent catalytic materials.


The catalytic activities of rare earth elements can be basically divided into two categories:

▶ Corresponding to the number of electrons in 4f orbitals (1-14), it changes monotonically, such as hydrogenation, dehydrogenation and ketone chemistry;

▶ Corresponding to the arrangement of electrons in 4f orbitals (1-7,7-14), it changes periodically, such as oxidation.


Advantages of rare earth catalysts: compared with traditional catalytic materials, rare earth catalysts have the characteristics of high catalytic activity, large specific surface area, good stability, high selectivity and short processing cycle. Compared with traditional precious metal catalysts, rare earth catalysts have strong advantages in resource abundance, cost, preparation process and performance.


The role of rare earth in catalysts




(1) Improve the oxygen storage capacity of the catalyst;

(2) Increase the dispersion of active metal and improve the catalytic activity of the active metal particle interface;

(3) Reduce the amount of precious metal;

(4) Improve the thermal stability of Al2O3 and other materials;

(5) Promote water gas conversion and steam reforming reaction;

(6) The activity of lattice oxygen is improved and the performance of the catalyst is significantly improved.


Classification of rare earth catalytic materials


▶ Relevant data show that there are three main types of rare earth catalytic materials that can be applied in industry


▶ According to different uses, rare earth catalytic materials are mainly divided into petroleum cracking catalysts, vehicle exhaust purification catalysts, catalytic combustion catalysts, synthetic rubber catalysts, photocatalysts and fuel cell catalysts.

Rare earth catalytic material industry chain


Application of rare earth catalytic materials




01. Automobile exhaust purification catalyst

▶ Main rare earth elements used: lanthanum, praseodymium, neodymium and cerium based materials

▶ The proportion of precious metals in the catalyst can be greatly reduced by adding rare earth components. In the support, rare earth is used to improve mechanical strength and thermal stability.


02. Petrochemical catalyst

▶ Main rare earth elements used: lanthanum and cerium

▶ It can improve the activity, selectivity, hydrothermal stability and vanadium poisoning resistance of molecular sieves, improve the yield of liquefied gas and olefins, and enhance the conversion ability of heavy oil.

▶ At present, the catalysts used in petrochemical industry consume more light rare earths.


03. Catalytic combustion catalyst

▶ Main rare earth elements used: lanthanum, praseodymium, cerium, samarium and gadolinium

▶ With its good examples and electronic conductivity, it is possible to completely adjust the conductivity of fuel cell electrode materials, electrolytes and link components, thereby improving the performance of solid oxide fuel cells.


04. Polymer material synthesis aid

▶ Main rare earth elements used: lanthanum, cerium and other light rare earths

▶ The product performance is non-toxic, efficient and multi-functional, which can significantly improve the processing performance and other properties of plastics. The market price is low, and the cost performance is better than traditional additives.


05. New energy field

▶ Solid oxide fuel cell


06. Environmental protection catalyst

▶ Purification of vehicle exhaust -- cerium oxide

▶ Organic wastewater treatment -- titanium oxide added with light rare earths to improve activity

▶ Catalytic purification of toxic waste gas


Research and analysis of rare earth catalytic materials


As early as the 1920s, there were studies on the catalysis of rare earth compounds. In 1924, Arthur Kennet goard of Trinity College, Cambridge reported the catalytic effect of cerium salt in the Royal Society of London. Richard Leslie Swan published an article in the Journal of the chemical society, transitions to discuss the catalytic effect of cerium and thorium oxides and their impact on weiersbach's mantle theory. In the following 70 years, the annual number of articles issued was more than 50. After a long period of technological germination, the annual number of publications exceeded 100 for the first time in 1991. The research of rare earth catalytic materials developed rapidly, and the output of achievements climbed at a relatively stable rate. It entered a rapid growth period, with an average annual growth rate of 8.6%, reaching 1733 in 2017, and showing a trend of continuous growth.


Distribution trend of rare earth catalytic materials


China accounts for 25% of the world's posts, far exceeding the United States, which ranks second (10%). Japan, India, France and Germany ranked third to sixth respectively, accounting for more than 5%. The United States, France, Japan and India were involved in this field earlier. After entering the period of rapid growth, Japan showed obvious quantitative advantages from 1993 to 2000. In 2002, China surpassed Japan for the first time in the annual number of documents issued, and maintained an absolute leading position after 2004. In 2018, China accounted for 38.7% of the world's number of documents issued, becoming the country with the largest number of rare earth catalytic materials in the world.




Patent analysis of rare earth catalytic materials


Applications for rare earth catalysis related technologies began in 1919, mainly including catalysts for catalyzing nitrogen and hydrogen synthesis reactions to produce ammonia, and catalysts for catalyzing ethylene to produce alcohol or ether. From the general trend of application, the patent application related to rare earth catalytic materials has generally gone through four stages:


(1) During the embryonic period of Technology (1919 ~ 1955), the number of patents was less than 50;

(2) Slow growth period (1956-1993): during this period, the annual number of patents increased from 98 in 1962 to more than 1000 in 1992;

(3) Rapid growth period (1994-2004): during this period, the growth of patent volume showed an accelerated trend, with an average annual growth rate of 13.47%;

(4) Fluctuating growth period (since 2006): during this period, the number of patents has shown a fluctuating growth trend, with more patents in 2016 and more than 4000 patents in 2018.


Trend of patent application in rare earth catalysis



China, the United States, Europe, Japan, Canada and South Korea are the countries / regions where the global patent authorities focus on layout and protection. Among them, there are 22286 catalytic patents in China; The United States ranked second with 13872 pieces; Europe ranked third with 7837 pieces and Japan with 4660 pieces.


Global market layout of rare earth catalysis related patents in 2018




Development trend of rare earth catalytic materials


The research and development of rare earth catalytic materials began in the 1920s. After a long period of technical accumulation, it entered a rapid development stage after 1991. In recent years, the research and development of rare earth catalytic materials are concentrated in China, the United States, Japan, India and other countries. Among them, the United States, France, Japan and India were involved in this field earlier. Japan briefly led the research and development activities. After the 20th century, China quickly overtook China to become a country with more rare earth catalytic materials in the world. China, the United States, Europe, Japan, Canada, South Korea, Australia, the United Kingdom and Taiwan, China are the countries / regions where the global patent authorities focus on layout and protection.


At present, the research and development trends of rare earth catalytic materials mainly focus on:

▶ Improve catalyst durability and reduce catalyst cost

▶ Develop rare earth modified vanadium free and vanadium less industrial exhaust denitration catalysts, new automobile exhaust purifiers that meet more advanced exhaust emission standards, cerium zirconium oxygen storage materials that improve the thermal stability and oxygen transmission capacity of catalysts, etc

▶ Optimization and improvement of electrode and electrolyte materials for solid fuel cells

▶ Improve catalyst performance, etc


Original rare earth center rare earth big data


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