Catalytic oxidation of formaldehyde at room temperature
1. Pt/TiO2 catalyst for ambient HCHO oxidation
For the first time in the world, we developed a highly efficient and stable Pt/TiO2 catalyst for the catalytic oxidation of formaldehyde (HCHO), achieving complete catalytic decomposition of formaldehyde into H2O and CO2 at room temperature without any external energy input. It was clarified that highly dispersed Pt species on TiO2 play the key role in determining the activity of the Pt/TiO2 catalyst for ambient HCHO destruction, and the reaction mechanism of HCHO oxidation over the noble metal catalyst was elucidated. (Catal. Commun., 2005, 6, 211; Appl. Catal. B, 2006, 65, 37; Catal. Today, 2007, 126, 345)
Performance of Pd/TiO2 catalyst for HCHO oxidation and reaction pathway of HCHO oxidation on Pd/TiO2 catalyst
2. Promotion effect of alkali metal ions and oxygen vacancies
It is observed that alkali metal ions have a significant promotion effect on the activity of Pt/TiO2 for ambient HCHO oxidation. The Na-free catalyst had low activity for HCHO oxidation, with HCHO conversion being only ca. 19% at room temperature. With 2% Na addition, 100% HCHO conversion to CO2 and H2O was measured. It was revealed that the alkali metal ions significantly promote the activity of Pt/TiO2 by inducing atomically dispersed Pt species, thereby opening a new low-temperature reaction pathway. (Angew. Chem. Int. Ed., 2012, 51, 9628）
The promotion effect of alkali metal addition on Pt/TiO2 catalyst for HCHO oxidation
and reaction pathway of HCHO oxidation on Pt/TiO2 catalyst.
We observed that Na doping also has a dramatic and common promotion effect on the Pd/TiO2 and Ir/TiO2 catalyst systems. It was revealed that Na species addition can facilitate the activation of H2O and chemisorbed oxygen, therefore resulting in high performance for the Na doped Pd- and Ir-based catalysts for ambient HCHO destruction. In addition, the synergistic effect of H2O and chemisorbed oxygen on HCHO oxidation was also illuminated. (Environ. Sci. Technol., 2014, 48, 5816; Catal. Sci. Technol., 2016, 6, 2289; Catal. Today, 2017, 281, 412; ACS Catal., 2018, 8, 11377)
The promotion effect of alkali metal addition on Pd- and Ir- based catalysts for HCHO oxidation
We discovered the promotion effect of high temperature reduction on Pd/TiO2 catalysts for HCHO oxidation. It was found that oxygen vacancies played vital roles in the abnormal phenomenon that high temperature reduction did not induce Pd aggregation, but rather enhanced Pd dispersion. The oxygen vacancies could not only trap the diffusing Pd particles but also facilitate the activation of H2O and chemisorbed oxygen. The work applied a new concept to design catalysts with high dispersion of supported noble metals. (Appl. Catal. B, 2017, 217, 560)
The promotion effect of high temperature reduction on Pd/TiO2 catalyst for HCHO oxidation
3. Practical applications of Pt-based catalyst
We have successfully implemented this basic research achievement into practical applications. New Air Cleaners equipped with the novel Pt-based catalyst have been developed and put into the Chinese market, and have already become the best-selling Air Cleaner in China, greatly improving indoor air quality and benefitting the Chinese people.
The application achievements of HCHO catalytic oxidation technology
19. Xueyan Chen, Min Chen, Guangzhi He, Fei Wang, Guangyan Xu, Yaobin Li, Changbin Zhang*, Hong He, “Specific role of potassium in promoting Ag/Al2O3 for catalytic oxidation of formaldehyde at low temperature”, J. Phys. Chem. C., 122, (2018) 27331-27339.
18. Yaobin Li, Xueyan Chen, Chunying Wang, Changbin Zhang*, Hong He, “Sodium enhances Ir/TiO2 activity for catalytic oxidation of formaldehyde at ambient temperature”, ACS Catal., 8, (2018) 11377-11385.
17. Yaobin Li, Changbin Zhang*, Jinzhu Ma, Min Chen,Hua Deng, Hong He*, “High temperature reduction dramatically promotes Pd/TiO2 catalyst for ambient formaldehyde oxidation”, Appl. Catal. B, 217, (2017) 560-569.
16. Yaobin Li, Changbin Zhang*, Hong He, “Significant enhancement in activity of Pd/TiO2 catalyst for formaldehyde oxidation by Na addition”, Catal.Today, 281, (2017) 412-417.
15. Yaobin Li, Changbin Zhang, Hong He*, Jianghao Zhang, Min Chen, “Influence of alkali metals on Pd/TiO2 catalysts for catalytic oxidation of formaldehyde at room temperature”, Catal. Sci. Technol., 6(7), (2016) 2289-2295.
14. Jianghao Zhang, Yaobin Li, Yan Zhang, Min Chen, Lian Wang, Changbin Zhang*, Hong He, “Effect of support on the activity of Ag-based catalysts for formaldehyde oxidation”, Sci. Rep., 5, (2015) 12950.
13. Jianghao Zhang, Yaobin Li, Lian Wang, Changbin Zhang*, Hong He. “Catalytic oxidation of formaldehyde over manganese oxides with different crystal structure”, Catal. Sci. Technol., 5(4), (2015) 2305-2313.
12. 张江浩，王亚飞，张长斌*，贺泓，“负载方式对Ag/CoO3催化剂催化氧化甲醛活性的影响”，化学工业与工程，32(3),(2015)67-72.
11. Changbin Zhang, Yaobin Li, Yafei Wang, Hong He*, “Sodium-promoted Pd/TiO2 for catalytic oxidation of formaldehyde at ambient temperature”, Environ. Sci. Technol., 48, (2014) 5816-5822.
10. Changbin Zhang, Fudong Liu, YanpingZhai, Hiroko Ariga, Nan Yi, Yongchun Liu, Kiyotaka Asakura, Maria Flytzani-Stephanopoulos*, Hong He*, “Alkali metal promoted Pt/TiO2 opens a more efficient pathway to formaldehyde oxidation at ambient temperatures”, Angew. Chem. Int. Ed., 2012, 51(38) 9628-9632.
9. Li Zhou, Junhui He*, Jie Zhang, Zhicheng He, Yucai Hu, Changbin Zhang, Hong He, “Facile in-situ synthesis of manganese dioxide nanosheets on cellulose fibers and their application in oxidative decomposition of formaldehyde”, J. Phys. Chem. C, 2011, 115, 16873-16878.
8. Ken-ichi Tanaka*, Masashi Shou, Hong He, Changbin Zhang, Daling Lu, “A CO-tolerant hydrogen fuel cell system designed by combining with an extremely active Pt/CNT catalyst”, Catal. Lett., 127, (2009) 148-151.
7. Hongwei Gao*, Tingxia Yan, Changbin Zhang, Hong He, “Theoretical and experimental analysis on vibrational spectra of formate species adsorbed on Cu-Al2O3 catalyst”, J. Mol. Struct. (THEOCHEM), 857, (2008) 38-43.
6. Hongmin Chen, Junhui He*, Changbin Zhang, Hong He, “Self-assembly of novel mesoporous manganese oxide nanostructures and their application in oxidative decomposition of formaldehyde”, J. Phys. Chem. C, 111, (2007) 18033-18038.
5. Changbin Zhang, Hong He*, “A comparative study of TiO2 supported noble metal catalysts for the oxidation of formaldehyde at room temperature”, Catal. Today, 126, (2007) 345-350.
4. Changbin Zhang, Hong He*, Ken-ichi Tanaka, “Catalytic performance and mechanism of a Pt/TiO2 catalyst for the oxidation of formaldehyde at room temperature”, Appl. Catal.B, 65, (2006) 37-43.
3. Xiaoyan Shi, Changbin Zhang, Hong He, Masashi Shou, Ken-ichi Tanaka*, Shinichi Sugihara, Yoshitaka Ando, “Activation of Pt/TiO2 catalysts by structural transformation of Pt-sites”, Catal. Lett., 107(1-2), (2006) 1-4.
2. Changbin Zhang, Xiaoyan Shi, Hongwei Gao, Hong He*, “The elimination of formaldehyde over Cu-Al2O3 at room temperature”, J. Environ. Sci., 17, (2005) 429-432.
1. Changbin Zhang, Hong He*, Ken-ichi Tanaka, “Perfect catalytic oxidation of formaldehyde over a Pt/TiO2 catalyst at room temperature”, Catal. Commun., 6, (2005) 211-214.
