Then, after spending 14 months as director of the Division of Science Policy and Capacity Building in the Natural Sciences sector for UNESCO in Paris, France, he returned to his role as executive director of TWAS in September 2017 until stepping down in November 2023 to teach at Worcester Polytechnic Institute.
In 2001, Rwandan President Paul Kagame appointed him to serve as Minister of Education, Science, Technology and Scientific Research.
Murenzi's scientific research has focused on applications of multidimensional continuous wavelet transforms to quantum mechanics;[7] image and video processing; and science and technology policy.
More precisely, he introduced in his PhD thesis the full two-dimensional continuous wavelet transform, including the rotation parameter.
After his thesis, Murenzi published a number of articles in scientific journals and contributed to many conferences, in general in collaboration with his former supervisor in Louvain, J-P. Antoine.